The lowest sound a person can hear. Overtones in the ear

Hearing loss is a pathological condition characterized by hearing loss and difficulty in understanding spoken language. It occurs quite often, especially in the elderly. However, today there is a trend towards an earlier development of hearing loss, including among young people and children. Depending on how weakened hearing is, hearing loss is divided into different degrees.

What are decibels and hertz

Any sound or noise can be characterized by two parameters: height and sound intensity.

Pitch

The pitch of a sound is determined by the number of vibrations of the sound wave and is expressed in hertz (Hz): the higher the hertz, the higher the tone. For example, the very first white key on the left on a conventional piano (“A” subcontroctave) produces a low sound at 27.500 Hz, while the very last white key on the right (“up to” the fifth octave) produces 4186.0 Hz.

The human ear is able to distinguish sounds within the range of 16–20,000 Hz. Anything less than 16 Hz is called infrasound, and anything over 20,000 is called ultrasound. Both ultrasound and infrasound are not perceived by the human ear, but can affect the body and psyche.

All in frequency audible sounds can be divided into high, medium and low frequencies. Low-frequency sounds are up to 500 Hz, mid-frequency - within 500-10,000 Hz, high-frequency - all sounds with a frequency of more than 10,000 Hz. The human ear, with the same impact force, hears mid-frequency sounds better, which are perceived as louder. Accordingly, low- and high-frequency sounds are “heard” quieter, or even “stop sounding” altogether. In general, after 40–50 years, the upper limit of audibility of sounds decreases from 20,000 to 16,000 Hz.

sound power

When exposed to the ear loud sound eardrum rupture may occur. In the picture below - a normal membrane, above - a membrane with a defect.

Any sound can affect the organ of hearing in different ways. It depends on its sound strength, or loudness, which is measured in decibels (dB).

Normal hearing is able to distinguish sounds ranging from 0 dB and above. When exposed to loud sound more than 120 dB.

The most comfortable human ear feels in the range up to 80-85 dB.

For comparison:

winter forest in calm weather - about 0 dB,
rustling of leaves in the forest, park - 20-30 dB,
ordinary colloquial speech, office work - 40-60 dB,
noise from the engine in the car - 70-80 dB,
loud screams - 85-90 dB,
thunder rolls - 100 dB,
a jackhammer at a distance of 1 meter from it - about 120 dB.

Degrees of hearing loss relative to loudness

The following degrees of hearing loss are usually distinguished:

Normal hearing - a person hears sounds in the range from 0 to 25 dB and above. He distinguishes the rustle of leaves, the singing of birds in the forest, the ticking wall clock and so on.
Hearing loss:

I degree (mild) - a person begins to hear sounds from 26-40 dB.
II degree (moderate) - the threshold for the perception of sounds starts from 40–55 dB.
III degree (severe) - hears sounds from 56-70 dB.
IV degree (deep) - from 71–90 dB.

Deafness is a condition when a person cannot hear a sound louder than 90 dB.

An abbreviated version of the degrees of hearing loss:

Light degree - the ability to perceive sounds less than 50 dB. A person understands colloquial speech almost in full at a distance of more than 1 m.
Medium degree - the threshold for the perception of sounds begins at a volume of 50–70 dB. Communication with each other is difficult, because in this case a person hears speech well at a distance of up to 1 m.
Severe degree - more than 70 dB. Speech of normal intensity is no longer audible or unintelligible near the ear. You have to scream or use a special hearing aid.

In everyday practical life, specialists can use another classification of hearing loss:

Normal hearing. A person hears conversational speech and whispers at a distance of more than 6 m.
Mild hearing loss. A person understands conversational speech from a distance of more than 6 m, but he hears a whisper no more than 3-6 meters away from him. The patient can distinguish speech even with extraneous noise.
Moderate degree of hearing loss. A whisper distinguishes at a distance of no more than 1-3 m, and ordinary conversational speech - up to 4-6 m. Speech perception may be disturbed by extraneous noise.
Significant degree of hearing loss. Conversational speech is heard no further than at a distance of 2-4 m, and a whisper - up to 0.5-1 m. There is an illegible perception of words, some individual phrases or words have to be repeated several times.
Severe degree. Whisper is almost indistinguishable even at the very ear, colloquial speech, even when screaming, is hardly distinguished at a distance of less than 2 m. Reads lips more.

Degrees of hearing loss relative to pitch

I group. Patients are able to perceive only low frequencies in the range of 125–150 Hz. They only respond to low and loud voices.
II group. In this case, higher frequencies become available for perception, which are in the range from 150 to 500 Hz. Usually, simple colloquial vowels "o", "y" become distinguishable for perception.
III group. Good perception of low and medium frequencies (up to 1000 Hz). Such patients already listen to music, distinguish the doorbell, hear almost all vowels, catch the meaning simple phrases and individual words.
IV group. Become accessible to the perception of frequencies up to 2000 Hz. Patients distinguish almost all sounds, as well as individual phrases and words. They understand speech.

This classification of hearing loss is important not only for correct selection hearing aid, but also the definition of children in a regular or specialized school for .

Diagnosis of hearing loss

Audiometry can help determine the degree of hearing loss in a patient.

The most accurate reliable way to identify and determine the degree of hearing loss is audiometry. For this purpose, the patient is put on special headphones, into which a signal of appropriate frequencies and strength is applied. If the subject hears a signal, then he lets know about it by pressing the button of the device or by nodding his head. According to the results of audiometry, an appropriate curve is built auditory perception(audiogram), the analysis of which allows not only to identify the degree of hearing loss, but also in some situations to get a more in-depth understanding of the nature of hearing loss.
Sometimes, when performing audiometry, they do not wear headphones, but use a tuning fork or simply pronounce certain words at some distance from the patient.

When to See a Doctor

It is necessary to contact an ENT doctor if:

You began to turn your head towards the one who is speaking, and at the same time strain to hear him.
Relatives living with you or friends who have come to visit make a remark about the fact that you turned on the TV, radio, player too loudly.
The doorbell is now not as clear as before, or you have stopped hearing it altogether.
When talking on the phone, you ask the other person to speak louder and more clearly.
They began to ask you to repeat what you were told again.
If there is noise around, then it becomes much more difficult to hear the interlocutor and understand what he is talking about.

Despite the fact that, in general, the sooner the correct diagnosis is made and treatment is started, the better the results and the more likely it is that hearing will persist for many years to come.

February 7, 2018

Often people (even those who are well versed in the matter) have confusion and difficulty in clearly understanding how exactly the frequency range of sound heard by a person is divided into general categories (low, medium, high) and narrower subcategories (upper bass, lower mid and so on.). At the same time, this information is extremely important not only for experiments with car audio, but also useful for general development. Knowledge will definitely come in handy when setting up an audio system of any complexity and, most importantly, it will help to correctly assess the strengths or weaknesses of a particular speaker system or the nuances of the room listening to music (in our case, the interior of the car is more relevant), because it has a direct impact on the final sound. If there is a good and clear understanding of the predominance of certain frequencies in the sound spectrum by ear, then it is elementary and quickly possible to assess the sound of a particular musical composition, while clearly hearing the influence of room acoustics on sound coloring, the contribution of the acoustic system itself to sound and more subtly to make out all the nuances, which is what the ideology of "hi-fi" sounding strives for.

Division of the audible range into three main groups

The terminology of the division of the audible frequency spectrum came to us partly from the musical, partly from the scientific worlds, and in general it is familiar to almost everyone. The simplest and most understandable division that can experience the frequency range of sound in general terms is as follows:

low frequencies. The limits of the low frequency range are within 10 Hz ( bottom line) - 200 Hz (upper limit). The lower limit starts exactly from 10 Hz, although in the classical view a person is able to hear from 20 Hz (everything below falls into the infrasound region), the remaining 10 Hz can still be partially heard, as well as felt tactilely in the case of deep low bass and even influence on mental attitude person.
The low-frequency range of sound has the function of enrichment, emotional saturation and final response - if the failure in the low-frequency part of the acoustics or the original recording is strong, then this will not affect the recognition of a particular composition, melody or voice, but the sound will be perceived poorly, impoverished and mediocre, while subjectively being sharper and sharper in terms of perception, since the mids and highs will bulge and dominate against the background of the absence of a good saturated bass region.

Enough a large number of musical instruments reproduce sounds in the low frequency range, including male vocals can fall into the region of up to 100 Hz. The most pronounced instrument that plays from the very beginning of the audible range (from 20 Hz) can safely be called a wind organ.
Medium frequencies. The limits of the mid-frequency range are within 200 Hz (lower limit) - 2400 Hz (upper limit). The middle range will always be fundamental, defining and actually form the basis of the sound or music of the composition, therefore its importance cannot be overestimated.
This is explained in many ways, but mainly this feature human auditory perception is determined by evolution - it has happened over the many years of our formation that the hearing aid most sharply and clearly captures the mid-frequency range, because. within it is human speech, and it is the main tool for effective communication and survival. This also explains some non-linearity of auditory perception, which is always aimed at the predominance of medium frequencies when listening to music, because. our hearing aid is most sensitive to this range, and also automatically adjusts to it, as if "amplifying" more against the background of other sounds.

The vast majority of sounds, musical instruments or vocals are in the middle range, even if a narrow range is affected from above or below, then the range usually extends to the upper or lower middle anyway. Accordingly, vocals (both male and female) are located in the mid-frequency range, as well as almost all well-known instruments, such as: guitar and other strings, piano and other keyboards, wind instruments, etc.
High frequencies. The boundaries of the high frequency range are within 2400 Hz (lower limit) - 30000 Hz (upper limit). The upper limit, as in the case of the low-frequency range, is somewhat arbitrary and also individual: the average person cannot hear above 20 kHz, but there are rare people with sensitivity up to 30 kHz.
Also, a number of musical overtones can theoretically go into the region above 20 kHz, and as you know, the overtones are ultimately responsible for the coloring of the sound and the final timbre perception of the whole sound picture. Seemingly "inaudible" ultrasonic frequencies can clearly affect the psychological state of a person, although they will not be heard in the usual manner. Otherwise, the role of high frequencies, again by analogy with low ones, is more enriching and complementary. Although the high-frequency range has a much greater impact on the recognition of a particular sound, the reliability and preservation of the original timbre than the low-frequency section. High frequencies give music tracks "airiness", transparency, purity and clarity.

Many musical instruments also play in the high frequency range, including vocals that can go into the region of 7000 Hz and above with the help of overtones and harmonics. The most pronounced group of instruments in the high-frequency segment are strings and winds, and cymbals and violin reach almost the upper limit of the audible range (20 kHz) more fully in sound.

In any case, the role of absolutely all frequencies in the range audible to the human ear is impressive, and problems in the path at any frequency are likely to be clearly visible, especially to a trained hearing aid. The goal of reproducing high-fidelity hi-fi sound of class (or higher) is to ensure that all frequencies sound as accurately and as evenly as possible with each other, as it happened at the time the soundtrack was recorded in the studio. The presence of strong dips or peaks in the frequency response of the acoustic system indicates that, due to their design features it is not capable of reproducing music as originally intended by the author or sound engineer at the time of recording.

Listening to music, a person hears a combination of the sound of instruments and voices, each of which sounds in some segment of its own. frequency range. Some instruments may have a very narrow (limited) frequency range, while others, on the contrary, can literally extend from the lower to the upper audible limit. It must be taken into account that despite the same intensity of sounds on different frequencies ranges, human ear perceives these frequencies with different loudness, which is again due to the mechanism of the biological device of the hearing aid. The nature of this phenomenon is also explained in many respects by the biological necessity of adaptation mainly to the mid-frequency sound range. So in practice, a sound having a frequency of 800 Hz at an intensity of 50 dB will be perceived subjectively by ear as louder than a sound of the same strength, but with a frequency of 500 Hz.

Moreover, different sound frequencies flooding the audible frequency range of sound will have different threshold pain sensitivity! pain threshold considered as a standard middle frequency 1000 Hz with a sensitivity of approximately 120 dB (may vary slightly depending on the individual). As in the case of uneven perception of intensity at different frequencies at normal volume levels, approximately the same dependence is observed with respect to the pain threshold: it occurs most quickly at medium frequencies, but at the edges of the audible range, the threshold becomes higher. For comparison, the pain threshold at an average frequency of 2000 Hz is 112 dB, while the pain threshold at a low frequency of 30 Hz will be already 135 dB. Pain threshold for low frequencies always higher than medium and high.

A similar disparity is observed with respect to hearing threshold is the lower threshold after which sounds become audible to the human ear. Conventionally, the threshold of hearing is considered to be 0 dB, but again it is true for the reference frequency of 1000 Hz. If, for comparison, we take a low-frequency sound with a frequency of 30 Hz, then it will become audible only at a wave emission intensity of 53 dB.

The listed features of human auditory perception, of course, have a direct impact when the question of listening to music and achieving a certain psychological effect perception. We remember from that sounds with an intensity above 90 dB are harmful to health and can lead to degradation and significant hearing impairment. But at the same time, too quiet low-intensity sound will suffer from strong frequency unevenness due to the biological characteristics of auditory perception, which is non-linear in nature. Thus, a musical path with a volume of 40-50 dB will be perceived as depleted, with a pronounced lack (one might say a failure) of low and high frequencies. The named problem is well and long known, to combat it even a well-known function called loudness compensation, which, by equalization, equalizes the levels of low and high frequencies close to the level of the middle, thereby eliminating an unwanted drop without the need to raise the volume level, making the audible frequency range of sound subjectively uniform in terms of the degree of distribution of sound energy.

Taking into account the interesting and unique features of human hearing, it is useful to note that with an increase in sound volume, the frequency non-linearity curve flattens out, and at about 80-85 dB (and higher) the sound frequencies will become subjectively equivalent in intensity (with a deviation of 3-5 dB). Although the alignment is not complete and the graph will still be visible, albeit smoothed, but a curved line, which will maintain a tendency towards the predominance of the intensity of the middle frequencies compared to the rest. In audio systems, such unevenness can be solved either with the help of an equalizer, or with the help of separate volume controls in systems with separate channel-by-channel amplification.

Dividing the audible range into smaller subgroups

In addition to the generally accepted and well-known division into three general groups, sometimes it becomes necessary to consider one or another narrow part in more detail and in detail, thereby dividing the frequency range of the sound into even smaller "fragments". Thanks to this, a more detailed division appeared, using which you can simply quickly and fairly accurately indicate the intended segment of the sound range. Consider this division:

A small select number of instruments descend into the region of the lowest bass, and even more so sub-bass: double bass (40-300 Hz), cello (65-7000 Hz), bassoon (60-9000 Hz), tuba (45-2000 Hz), horns (60-5000Hz), bass guitar (32-196Hz), bass drum (41-8000Hz), saxophone (56-1320Hz), piano (24-1200Hz), synthesizer (20-20000Hz) , organ (20-7000 Hz), harp (36-15000 Hz), contrabassoon (30-4000 Hz). The indicated ranges include all the harmonics of the instruments.

Upper bass (80 Hz to 200 Hz) represented by the high notes of classical bass instruments, as well as the lowest audible frequencies of individual strings, such as the guitar. The upper bass range is responsible for the sensation of power and the transmission of the energy potential of the sound wave. It also gives a feeling of drive, the upper bass is designed to fully reveal the percussive rhythm of dance compositions. In contrast to the lower bass, the upper one is responsible for the speed and pressure of the bass region and the entire sound, therefore, in a high-quality audio system, it is always expressed as fast and biting, as a tangible tactile impact at the same time as the direct perception of sound.

Therefore, it is the upper bass that is responsible for the attack, pressure and musical drive, and only this narrow segment of the sound range can give the listener the feeling of the legendary "punch" (from the English punch - blow), when a powerful sound is perceived by a tangible and strong blow to the chest. Thus, it is possible to recognize a well-formed and correct fast upper bass in a musical system by the high-quality working out of an energetic rhythm, a collected attack, and by the well-formed instruments in the lower register of notes, such as cello, piano or wind instruments.

In audio systems, it is most expedient to give a segment of the upper bass range to mid-bass speakers of a fairly large diameter 6.5 "-10" and with good power indicators, a strong magnet. The approach is explained by the fact that it is precisely these speakers in terms of configuration that will be able to fully reveal the energy potential inherent in this very demanding region of the audible range.
But do not forget about the detail and intelligibility of the sound, these parameters are also important in the process of recreating a particular musical image. Since the upper bass is already well localized / defined in space by ear, the range above 100 Hz must be given exclusively to front-mounted speakers that will form and build the scene. In the segment of the upper bass, a stereo panorama is perfectly heard, if it is provided for by the recording itself.

The upper bass area already covers enough big number instruments and even low pitched male vocals. Therefore, among the instruments are the same ones that played low bass, but many others are added to them: toms (70-7000 Hz), snare drum (100-10000 Hz), percussion (150-5000 Hz), tenor trombone (80-10000 Hz), trumpet (160-9000 Hz), tenor saxophone (120-16000 Hz), alto saxophone (140-16000 Hz), clarinet (140-15000 Hz), alto violin (130-6700 Hz), guitar (80-5000 Hz). The indicated ranges include all the harmonics of the instruments.

Lower mid (200 Hz to 500 Hz)- the most extensive area, capturing most of the instruments and vocals, both male and female. Since the lower-mid range area actually transitions from the energetically saturated upper bass, it can be said that it "takes over" and is also responsible for the correct transfer of the rhythm section in conjunction with the drive, although this influence is already declining towards the clean mid-range frequencies.

In this range, the lower harmonics and overtones that fill the voice are concentrated, so it is extremely important for the correct transmission of vocals and saturation. It is also in the lower middle that the entire energy potential of the performer's voice is located, without which there will be no corresponding return and emotional response. By analogy with the transmission of the human voice, many live instruments also hide their energy potential in this segment of the range, especially those whose lower audible limit starts from 200-250 Hz (oboe, violin). The lower middle allows you to hear the melody of the sound, but does not make it possible to clearly distinguish the instruments.

Accordingly, the lower middle is responsible for correct design most instruments and voices, saturating the latter and making them recognizable by timbre coloring. Also, the lower middle is extremely demanding in terms of the correct transmission of a full-fledged bass range, since it "picks up" the drive and attack of the main percussion bass and is expected to properly support it and smoothly "finish", gradually reducing it to nothing. The sensations of sound purity and intelligibility of the bass lie precisely in this area, and if there are problems in the lower middle from an overabundance or the presence of resonant frequencies, then the sound will tire the listener, it will be dirty and slightly mumbling.
If there is a shortage in the region of the lower middle, then the correct feeling of the bass and the reliable transmission of the vocal part, which will be devoid of pressure and energy return, will suffer. The same applies to most instruments that, without the support of the lower middle, will lose their "face", become incorrectly framed and their sound will become noticeably poorer, even if it remains recognizable, it will no longer be so full.

When building an audio system, the range of the lower middle and above (up to the top) is usually given to mid-range speakers (MF), which, without a doubt, should be located in the front part in front of the listener and build the stage. For these speakers, the size is not so important, it can be 6.5 "and lower, how important is the detail and the ability to reveal the nuances of sound, which is achieved by the design features of the speaker itself (diffuser, suspension and other characteristics).
Also, correct localization is vital for the entire mid-frequency range, and literally the slightest tilt or turn of the speaker can have a tangible impact on the sound in terms of the correct realistic reproduction of the images of instruments and vocals in space, although this will largely depend on the design features of the speaker cone itself.

The lower middle covers almost all existing instruments and human voices, although it does not play a fundamental role, but is still very important for the full perception of music or sounds. Among the instruments there will be the same set that was able to win back the lower range of the bass region, but others are added to them that start already from the lower middle: cymbals (190-17000 Hz), oboe (247-15000 Hz), flute (240- 14500 Hz), violin (200-17000 Hz). The indicated ranges include all the harmonics of the instruments.

Middle Mid (500 Hz to 1200 Hz) or just a pure middle, almost according to the theory of balance, this segment of the range can be considered fundamental and fundamental in sound and rightfully dubbed the "golden mean". In the presented segment of the frequency range, you can find the main notes and harmonics of the vast majority of instruments and voices. Clarity, intelligibility, brightness and piercing sound depend on the saturation of the middle. We can say that the whole sound, as it were, "spreads" to the sides from the base, which is the mid-frequency range.

In the event of a failure in the middle, the sound becomes boring and inexpressive, loses its sonority and brightness, the vocals cease to fascinate and actually disappear. Also, the middle is responsible for the intelligibility of the main information coming from the instruments and vocals (to a lesser extent, because consonants go in a higher range), helping to distinguish them well by ear. Most of the existing instruments come to life in this range, become energetic, informative and tangible, the same happens with vocals (especially female ones), which are filled with energy in the middle.

The mid-frequency fundamental range covers the absolute majority of the instruments that have already been listed earlier, and also reveals the full potential of male and female vocals. Only rare selected instruments start their lives at medium frequencies, playing in a relatively narrow range initially, for example, a small flute (600-15000 Hz).

Upper mid (1200 Hz to 2400 Hz) represents a very delicate and demanding section of the range, which must be handled carefully and carefully. In this area, there are not so many fundamental notes that make up the foundation of the sound of an instrument or voice, but a large number of overtones and harmonics, due to which the sound is colored, becomes sharp and bright. By controlling this region of the frequency range, one can actually play with the coloring of the sound, making it either lively, sparkling, transparent and sharp; or vice versa dryish, moderate, but at the same time more assertive and driving.

But overemphasizing this range has an extremely undesirable effect on the sound picture, because. it begins to noticeably cut the ear, irritate and even cause painful discomfort. Therefore, the upper middle requires a delicate and careful attitude with it, tk. due to problems in this area, it is very easy to spoil the sound, or, on the contrary, make it interesting and worthy. Usually, the coloring in the upper middle region largely determines the subjective aspect of the genre of the acoustic system.

Thanks to the upper middle, vocals and many instruments are finally formed, they become well distinguished by ear and sound intelligibility appears. This is especially true for the nuances of the reproduction of the human voice, because it is in the upper middle that the spectrum of consonants is placed and the vowels that appeared in the early ranges of the middle continue. In a general sense, the upper middle favorably emphasizes and fully reveals those instruments or voices that are saturated with upper harmonics, overtones. In particular, female vocals, many bowed, stringed and wind instruments are revealed in a truly lively and natural way in the upper middle.

The vast majority of instruments still play in the upper middle, although many are already represented only in the form of wraps and harmonicas. The exception is some rare ones, initially distinguished by a limited low-frequency range, for example, a tuba (45-2000 Hz), which ends its existence in the upper middle completely.

Low treble (2400 Hz to 4800 Hz)- this is a zone / area of increased distortion, which, if present in the path, usually becomes noticeable in this segment. The lower highs are also flooded with various harmonics of instruments and vocals, which at the same time play a very specific and important role in the final design of the musical image recreated artificially. The lower highs carry the main load of the high-frequency range. In sound, they are manifested for the most part by residual and well-listened harmonics of vocals (mainly female) and unceasing strong harmonics of some instruments, which complete the image with the final touches of natural sound coloring.

They practically do not play a role in terms of distinguishing instruments and recognizing voices, although the lower top remains a highly informative and fundamental area. In fact, these frequencies outline the musical images of instruments and vocals, they indicate their presence. In the event of a failure of the lower high segment of the frequency range, the speech will become dry, lifeless and incomplete, approximately the same thing happens with instrumental parts - the brightness is lost, the very essence of the sound source is distorted, it becomes distinctly incomplete and underformed.

In any normal audio system, the role of high frequencies is assumed by a separate speaker called a tweeter (high frequency). Usually small in size, it is undemanding to the input power (within reasonable limits) by analogy with the middle and especially the bass section, but it is also extremely important for the sound to play correctly, realistically and at least beautifully. The tweeter covers the entire audible high-frequency range from 2000-2400 Hz to 20000 Hz. In the case of high-frequency drivers, almost by analogy with the mid-range section, the correct physical location and directionality is very important, since the tweeters are maximally involved not only in the formation of the sound stage, but also in the process of fine-tuning it.

With the help of tweeters, you can largely control the scene, zoom in/out the performers, change the shape and flow of instruments, play with the color of the sound and its brightness. As in the case of adjusting midrange speakers, almost everything affects the correct sound of tweeters, and often very, very sensitively: turn and tilt of the speaker, its location vertically and horizontally, distance from nearby surfaces, etc. However, the success of the correct tuning and the finicky of the HF section depends on the design of the speaker and its polar pattern.

Instruments that play down to the lower highs, they do so predominantly through harmonics rather than fundamentals. Otherwise, in the lower high range, almost all the same ones that were in the mid-frequency segment "live", i.e. almost all existing ones. It is the same with the voice, which is especially active in the lower high frequencies, a special brightness and influence can be heard in the female vocal parts.

Medium high (4800 Hz to 9600 Hz) The mid-high frequency range is often considered the limit of perception (for example, according to medical terminology), although in practice this is not true and depends both on the individual characteristics of the person and on his age (the older the person, the more the perception threshold decreases). In the musical path, these frequencies give a feeling of purity, transparency, "airiness" and a certain subjective completeness.

In fact, the presented segment of the range is comparable with increased clarity and detail of the sound: if there is no dip in the middle top, then the sound source is mentally well localized in space, concentrated at a certain point and expressed by a feeling of a certain distance; and vice versa, if there is a lack of lower top, then the clarity of the sound seems to be blurred and the images are lost in space, the sound becomes cloudy, clamped and synthetically unrealistic. Accordingly, the regulation of the lower high frequencies is comparable to the ability to virtually "move" the sound stage in space, i.e. move it away or bring it closer.

The mid-high frequencies ultimately provide the desired presence effect (more precisely, they complete it to the fullest, since the effect is based on deep and soulful bass), thanks to these frequencies, the instruments and voice become as realistic and reliable as possible. We can also say about the middle tops that they are responsible for the detail in the sound, for numerous small nuances and overtones both in relation to the instrumental part and in the vocal parts. At the end of the mid-high segment, "air" and transparency begin, which can also be quite clearly felt and influence perception.

Despite the fact that the sound is steadily declining, the following are still active in this segment of the range: male and female vocals, bass drum (41-8000 Hz), toms (70-7000 Hz), snare drum (100-10000 Hz) , Cymbals (190-17000 Hz), Air Support Trombone (80-10000 Hz), Trumpet (160-9000 Hz), Bassoon (60-9000 Hz), Saxophone (56-1320 Hz), Clarinet (140-15000 Hz), oboe (247-15000 Hz), flute (240-14500 Hz), piccolo (600-15000 Hz), cello (65-7000 Hz), violin (200-17000 Hz), harp (36-15000 Hz) ), organ (20-7000 Hz), synthesizer (20-20000 Hz), timpani (60-3000 Hz).

Upper high (9600 Hz to 30000 Hz) a very complex and incomprehensible range for many, providing for the most part support for certain instruments and vocals. The upper highs mainly provide the sound with the characteristics of airiness, transparency, crystallinity, some sometimes subtle addition and coloring, which may seem insignificant and even inaudible to many people, but still carries a very definite and specific meaning. When trying to build a sound high class"hi-fi" or even "hi-end" the highest high frequencies are given the closest attention, because. it is rightly believed that not the slightest detail can be lost in sound.

In addition, in addition to the immediate audible part, the upper high region, smoothly turning into ultrasonic frequencies, can still have some psychological effect: even if these sounds are not heard clearly, the waves are radiated into space and can be perceived by a person, while more at the level mood formation. They also ultimately affect the sound quality. In general, these frequencies are the most subtle and gentle in the entire range, but they are also responsible for the feeling of beauty, elegance, sparkling aftertaste of music. With a lack of energy in the upper high range, it is quite possible to feel discomfort and musical understatement. In addition, the capricious upper high range gives the listener a sense of spatial depth, as if diving deep into the stage and being enveloped in sound. However, an excess of sound saturation in the indicated narrow range can make the sound unnecessarily "sandy" and unnaturally thin.

When discussing the upper high frequency range, it is also worth mentioning the tweeter called the "super tweeter", which is actually a structurally expanded version of the conventional tweeter. Such a speaker is designed to cover a larger portion of the range in the upper side. If the operating range of a conventional tweeter ends at the expected limiting mark, above which the human ear theoretically does not perceive sound information, i.e. 20 kHz, then the super tweeter can raise this border to 30-35 kHz.

The idea pursued by the implementation of such a sophisticated speaker is very interesting and curious, it came from the world of "hi-fi" and "hi-end", where it is believed that no frequencies in the musical path can be ignored and, even if we do not hear them directly, they are still initially present during the live performance of a particular composition, which means that they can indirectly have some kind of influence. The situation with the super tweeter is complicated only by the fact that not all equipment (sound sources/players, amplifiers, etc.) is capable of outputting a signal in the full range, without cutting frequencies from above. The same is true for the recording itself, which is often done with a cut in the frequency range and loss of quality.

Approximately in the way described above, the division of the audible frequency range into conditional segments looks like in reality, with the help of division it is easier to understand problems in the audio path in order to eliminate them or to equalize the sound. Despite the fact that each person imagines some kind of exclusively his own and understandable only to him reference image of sound in accordance only with his taste preferences, the nature of the original sound tends to balance, or rather to average all sounding frequencies. Therefore, the correct studio sound is always balanced and calm, the entire spectrum of sound frequencies in it tends to a flat line on the frequency response (amplitude-frequency response) graph. The same direction is trying to implement uncompromising "hi-fi" and "hi-end": to get the most even and balanced sound, without peaks and dips throughout the entire audible range. Such a sound, by its nature, may seem boring and inexpressive, devoid of brightness and of no interest to an ordinary inexperienced listener, but it is precisely this sound that is truly correct in fact, striving for balance by analogy with how the laws of the very universe in which we live manifest themselves. .

One way or another, the desire to recreate some specific character of sound within your audio system lies entirely with the preferences of the listener. Some people like the sound with predominantly powerful lows, others like the increased brightness of the "raised" highs, others can enjoy hours of harsh vocals accentuated in the middle ... Perception options can be great multitude, and information about the frequency division of the range into conditional segments will just help anyone who wants to create the sound of their dreams, only now with a more complete understanding of the nuances and subtleties of those laws that sound as a physical phenomenon obeys.

Understanding the process of saturation with certain frequencies of the sound range (filling it with energy in each of the sections) in practice will not only facilitate the tuning of any audio system and make it possible to build a scene in principle, but will also give invaluable experience in assessing the specific nature of the sound. With experience, a person will be able to instantly determine the shortcomings of sound by ear, moreover, very accurately describe problems in a certain part of the range and suggest Possible Solution to improve the sound picture. Sound correction can be carried out by various methods, where you can use an equalizer as "levers", for example, or you can "play" with the location and direction of the speakers - thereby changing the character early reflections waves, eliminating standing waves, etc. This will already be a "completely different story" and a topic for separate articles.

The frequency range of the human voice in musical terminology

Separately and separately in music, the role of the human voice as a vocal part is assigned, because the nature of this phenomenon is truly amazing. The human voice is so multifaceted and its range (compared to musical instruments) is the widest, with the exception of some instruments, such as the pianoforte.
Moreover, in different ages a person can make sounds of different pitch, in childhood to ultrasonic heights, in adulthood, the male voice is quite capable of descending extremely low. Here, as before, it is extremely important individual characteristics vocal cords person, because there are people who can amaze with their voice in the range of 5 octaves!

Baby

Alto (low)
Soprano (high)
Treble (high in boys)

Men's

Bass profundo (extra low) 43.7-262 Hz
Bass (low) 82-349 Hz
Baritone (medium) 110-392 Hz
Tenor (high) 132-532 Hz
Tenor altino (extra high) 131-700 Hz

Women's

Contralto (low) 165-692 Hz
Mezzo-soprano (medium) 220-880 Hz
Soprano (high) 262-1046 Hz
Coloratura soprano (extra high) 1397 Hz

For our orientation in the world around us, hearing plays the same role as vision. The ear allows us to communicate with each other using sounds; it has a special sensitivity to the sound frequencies of speech. With the help of the ear, a person picks up various sound vibrations in the air. Vibrations that come from an object (sound source) are transmitted through the air, which plays the role of a sound transmitter, and are caught by the ear. The human ear perceives air vibrations with a frequency of 16 to 20,000 Hz. Vibrations with a higher frequency are ultrasonic, but the human ear does not perceive them. The ability to distinguish high tones decreases with age. The ability to pick up sound with two ears makes it possible to determine where it is. In the ear, air vibrations are converted into electrical impulses, which are perceived by the brain as sound.

In the ear there is also an organ for perceiving the movement and position of the body in space - vestibular apparatus . The vestibular system plays an important role in the spatial orientation of a person, analyzes and transmits information about accelerations and decelerations of rectilinear and rotational movements, as well as changes in the position of the head in space.

ear structure

Based on the external structure, the ear is divided into three parts. The first two parts of the ear, outer (outer) and middle, conduct sound. The third part - the inner ear - contains auditory cells, mechanisms for the perception of all three features of sound: pitch, strength and timbre.

outer ear- the protruding part of the outer ear is called auricle, its basis is a semi-rigid supporting tissue - cartilage. The anterior surface of the auricle has a complex structure and an inconsistent shape. It is made up of cartilage and fibrous tissue, with the exception of the lower part - the lobules (ear lobe) formed by fatty tissue. At the base of the auricle, there is an anterior, superior, and posterior ear muscles, whose movements are limited.

In addition to the acoustic (sound-catching) function, the auricle performs a protective role, protecting the ear canal into the eardrum from harmful effects. environment(water, dust, strong air currents). Both the shape and size of the auricles are individual. The length of the auricle in men is 50–82 mm and the width is 32–52 mm; in women, the dimensions are slightly smaller. On a small area of the auricle, all the sensitivity of the body and internal organs is represented. Therefore, it can be used to obtain biologically important information about the state of any organ. The auricle concentrates sound vibrations and directs them to the external auditory opening.

External auditory canal serves to carry out sound vibrations air from the auricle to the eardrum. The external auditory meatus has a length of 2 to 5 cm. Its outer third is formed cartilage tissue, and the internal 2/3 - bone. The external auditory meatus is arcuately curved in the upper-posterior direction, and easily straightens when the auricle is pulled up and back. In the skin of the ear canal are special glands secreting a secret yellowish color(earwax), the function of which is to protect the skin from bacterial infection and foreign particles (insect ingress).

The external auditory canal is separated from the middle ear by the tympanic membrane, which is always retracted inward. This is a thin connective tissue plate, covered on the outside with a stratified epithelium, and on the inside with a mucous membrane. The external auditory canal conducts sound vibrations to the tympanic membrane, which separates the outer ear from the tympanic cavity (middle ear).

Middle ear, or tympanic cavity, is a small air-filled chamber that is located in the pyramid of the temporal bone and is separated from the external auditory canal by the tympanic membrane. This cavity has bony and membranous (eardrum) walls.

Eardrum is a 0.1 µm thick, sedentary membrane woven from fibers that go in different directions and are unevenly stretched in different areas. Due to this structure, the tympanic membrane does not have its own period of oscillation, which would lead to increased sound signals, coinciding with the frequency of natural oscillations. It begins to oscillate under the action of sound vibrations passing through the external auditory meatus. The tympanic membrane communicates with the mastoid cave through an opening in the posterior wall.

The opening of the auditory (Eustachian) tube is located in the anterior wall of the tympanic cavity and leads to the nasal part of the pharynx. Thereby atmospheric air may enter the tympanic cavity. Normally, the opening of the Eustachian tube is closed. It opens during swallowing or yawning, helping to equalize air pressure on the eardrum from the side of the middle ear cavity and the external auditory opening, thereby protecting it from ruptures that lead to hearing loss.

In the tympanic cavity lie auditory ossicles. They are very small in size and are connected in a chain that extends from the eardrum to inner wall tympanic cavity.

The outermost bone hammer- its handle is connected to the eardrum. The head of the malleus is connected to the incus, which is movably articulated with the head stirrup.

The auditory ossicles are so named because of their shape. The bones are covered with a mucous membrane. Two muscles regulate the movement of the bones. The connection of the bones is such that it contributes to increased pressure sound waves on the membrane of the oval window by 22 times, which allows weak sound waves to set the liquid in motion in snail.

inner ear enclosed in the temporal bone and is a system of cavities and canals located in the bone substance of the petrous part of the temporal bone. Together, they form a bony labyrinth, inside of which is a membranous labyrinth. Bone labyrinth It is a bone cavity of various shapes and consists of the vestibule, three semicircular canals and the cochlea. membranous labyrinth consists of a complex system of the finest membranous formations located in the bony labyrinth.

All cavities of the inner ear are filled with fluid. Inside the membranous labyrinth is endolymph, and the fluid washing the membranous labyrinth from the outside is relymph and is similar in composition to cerebrospinal fluid. Endolymph differs from relymph (it has more potassium ions and less sodium ions) - it carries a positive charge in relation to relymph.

vestibule - central part bony labyrinth, which communicates with all its parts. Behind the vestibule are three bony semicircular canals: superior, posterior, and lateral. The lateral semicircular canal lies horizontally, the other two are at right angles to it. Each channel has an extended part - an ampoule. Inside it contains a membranous ampulla filled with endolymph. When the endolymph moves during a change in the position of the head in space, the nerve endings are irritated. The nerve fibers carry the impulse to the brain.

Snail is a spiral tube forming two and a half turns around a cone-shaped bone rod. It is the central part of the organ of hearing. Inside the bony canal of the cochlea there is a membranous labyrinth, or cochlear duct, to which the ends of the cochlear part of the eighth cranial nerve The vibrations of the perilymph are transmitted to the endolymph of the cochlear duct and activate the nerve endings of the auditory part of the eighth cranial nerve.

The vestibulocochlear nerve consists of two parts. The vestibular part conducts nerve impulses from the vestibule and semicircular canals to the vestibular nuclei of the pons and medulla oblongata and further to the cerebellum. The cochlear part transmits information along the fibers that follow from the spiral (Corti) organ to the auditory trunk nuclei and then - through a series of switches in the subcortical centers - to the cortex upper division temporal lobe cerebral hemispheres.

The mechanism of perception of sound vibrations

Sounds are produced by vibrations in the air and are amplified in the auricle. The sound wave is then conducted along the outer ear canal to the eardrum, causing it to vibrate. The vibration of the tympanic membrane is transmitted to the chain auditory ossicles: hammer, anvil and stirrup. The base of the stirrup is fixed to the window of the vestibule with the help of an elastic ligament, due to which the vibrations are transmitted to the perilymph. In turn, through the membranous wall of the cochlear duct, these vibrations pass to the endolymph, the movement of which causes irritation. receptor cells spiral organ. The resulting nerve impulse follows the fibers of the cochlear part of the vestibulocochlear nerve to the brain.

The translation of sounds perceived by the ear as pleasant and unpleasant sensations is carried out in the brain. Irregular sound waves form sensations of noise, while regular, rhythmic waves are perceived as musical tones. Sounds propagate at a speed of 343 km/s at an air temperature of 15–16ºС.

When transmitting vibrations through the air, and up to 220 kHz when transmitting sound through the bones of the skull. These waves have important biological significance, for example, sound waves in the range of 300-4000 Hz correspond to the human voice. Sounds above 20,000 Hz are of little practical value, as they are quickly decelerated; vibrations below 60 Hz are perceived through the vibrational sense. The range of frequencies that humans can hear is called auditory or sound range; higher frequencies are called ultrasonic, while lower frequencies are called infrasound.

Physiology of hearing

The ability to distinguish sound frequencies is highly dependent on a particular person: his age, gender, susceptibility to auditory diseases, training and hearing fatigue. Individuals are able to perceive sound up to 22 kHz, and possibly even higher.

Some animals can hear sounds that are not audible to humans (ultrasound or infrasound). Bats use ultrasound for echolocation during flight. Dogs are able to hear ultrasound, which is the basis for the work of silent whistles. There is evidence that whales and elephants can use infrasound to communicate.

A person can distinguish several sounds at the same time due to the fact that there can be several standing waves in the cochlea at the same time.

To satisfactorily explain the phenomenon of hearing has proved to be an extraordinarily difficult task. A person who came up with a theory that would explain the perception of pitch and loudness of sound would almost certainly guarantee himself a Nobel Prize.
original text(English)

Explaining hearing adequately has proven a singularly difficult task. One would almost ensure oneself a Nobel prize by presenting a theory explaining satisfactorily no more than the perception of pitch and loudness.

- Reber, Arthur S., Reber (Roberts), Emily S. The Penguin Dictionary of Psychology. - 3rd edition. - London: Penguin Books Ltd, . - 880 p. - ISBN 0-14-051451-1, ISBN 978-0-14-051451-3

At the beginning of 2011, a brief report about the joint work of the two Israeli institutes was published in separate scientific media. IN human brain specialized neurons have been identified that make it possible to estimate the pitch of a sound, up to 0.1 tone. Animals, except for bats, do not possess such a device, and for different types accuracy is limited to 1/2 to 1/3 octaves. (Attention! This information requires clarification!)

Psychophysiology of hearing

Projection of auditory sensations

No matter how auditory sensations arise, we usually refer them to the external world, and therefore we always look for the reason for the excitation of our hearing in vibrations received from the outside from one distance or another. This feature is much less pronounced in the sphere of hearing than in the sphere of visual sensations, which are distinguished by their objectivity and strict spatial localization and are probably also acquired through long experience and control of other senses. With auditory sensations, the ability to project, objectify and spatially localize cannot reach such high degrees as with visual sensations. This is due to such features of the structure of the hearing aid, such as, for example, the lack muscle mechanisms, depriving it of the possibility of precise spatial definitions. We know the enormous significance that muscular feeling has in all spatial definitions.

Judgments about the distance and direction of sounds

Our judgments about the distance at which sounds are emitted are very inaccurate, especially if the person's eyes are closed and he does not see the source of the sounds and the surrounding objects, by which one can judge the "acoustics of the environment" based on life experience, or the acoustics of the environment is atypical: for example, in an acoustic anechoic chamber, the voice of a person who is only a meter away from the listener seems to the latter many times and even tens of times more distant. Also, familiar sounds seem closer to us the louder they are, and vice versa. Experience shows that we are less mistaken in determining the distance of noises than musical tones. A person’s ability to judge the direction of sounds is very limited: not having auricles that are mobile and convenient for collecting sounds, in cases of doubt, he resorts to head movements and puts it in a position in which sounds differ the best way, that is, the sound is localized by a person in the direction from which it is heard stronger and “clearer”.

Three mechanisms are known by which the direction of sound can be distinguished:

Difference in average amplitude (historically the first principle to be discovered): For frequencies above 1 kHz, that is, those with a wavelength smaller than the size of the listener's head, the sound reaching the near ear has a greater intensity.
Phase Difference: Branching neurons are able to distinguish phase shifts of up to 10-15 degrees between the arrival of sound waves in the right and left ear for frequencies in the approximate range of 1 to 4 kHz (corresponding to an accuracy of 10 µs in timing of arrival).
The difference in the spectrum: the folds of the auricle, the head and even the shoulders introduce small frequency distortions into the perceived sound, absorbing different harmonics in different ways, which is interpreted by the brain as Additional Information about horizontal and vertical localization of sound.

The ability of the brain to perceive the described differences in the sound heard by the right and left ear led to the creation of binaural recording technology.

The described mechanisms do not work in water: determining the direction by the difference in loudness and spectrum is impossible, since the sound from the water passes almost without loss directly to the head, and therefore to both ears, which is why the volume and spectrum of sound in both ears at any location of the source sound with high fidelity are the same; determining the direction of the sound source by phase shift is impossible, because due to the much higher speed of sound in water, the wavelength increases several times, which means that the phase shift decreases many times.

From the description of the above mechanisms, the reason for the impossibility of determining the location of low-frequency sound sources is also clear.

Hearing study

Hearing is tested using a special device or computer program called an "audiometer".

The frequency characteristics of hearing are also determined, which is important when staging speech in hearing-impaired children.

Norm

The perception of the frequency range 16 Hz - 22 kHz changes with age - high frequencies are no longer perceived. A decrease in the range of audible frequencies is associated with changes in the inner ear (cochlea) and with the development of sensorineural hearing loss with age.

hearing threshold

hearing threshold- the minimum sound pressure at which the sound of a given frequency is perceived by the human ear. The threshold of hearing is expressed in decibels. The sound pressure of 2 10 −5 Pa at a frequency of 1 kHz was taken as the zero level. The hearing threshold for a particular person depends on individual properties, age, and physiological state.

Threshold of pain

auditory pain threshold- the value of sound pressure at which pain occurs in the auditory organ (which is associated, in particular, with the achievement of the tympanic membrane extensibility limit). Exceeding this threshold results in acoustic trauma. The sensation of pain defines the limit of the dynamic range of human audibility, which averages 140 dB for a tone signal and 120 dB for noise with a continuous spectrum.

Pathology

Literature

Physical Encyclopedic Dictionary / Ch. ed. A. M. Prokhorov. Ed. collegium D. M. Alekseev, A. M. Bonch-Bruevich, A. S. Borovik-Romanov and others - M .: Sov. Encycl., 1983. - 928 p., p. 579

Links

Video lecture Auditory perception

Human organ systems

Cardiovascular system (heart, blood vessels) Lymphatic system Digestive system Endocrine system Immune system Sensory system (somatosensory system, visual system, olfactory sensory system, auditory sensory system, gustatory sensory system) Integumentary system Nervous system (central, peripheral) Musculoskeletal system (skeletal system, muscular system) genitourinary system (reproductive system, urinary system) Respiratory system

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Synonyms:

See what "Hearing" is in other dictionaries:

hearing- hearing, and ... Russian spelling dictionary

hearing- hearing / ... Morphemic spelling dictionary

Exist., m., use. often Morphology: (no) what? hearing and hearing, what? hearing, (seeing) what? hearing what? hearing about what? about hearing; pl. What? rumors, (no) what? rumors for what? rumors, (see) what? rumors what? rumors about what? about rumors perception by organs ... ... Dictionary of Dmitriev

Husband. one of the five senses by which sounds are recognized; instrument is his ear. Hearing dull, thin. In deaf and deaf animals, hearing is replaced by a sense of concussion. Go by ear, seek by ear. | A musical ear, an inner feeling that comprehends mutual ... ... Dahl's Explanatory Dictionary

Hearing, m. 1. only units. One of the five external senses, giving the ability to perceive sounds, the ability to hear. The ear is the organ of hearing. acute hearing. A hoarse cry reached his ears. Turgenev. “I wish glory, so that your hearing will be amazed by my name ... Explanatory Dictionary of Ushakov

The video made by AsapSCIENCE is a kind of age-related hearing loss test that will help you know the limits of your hearing.

Various sounds are played in the video, starting at 8000 Hz, which means you are not hearing impaired.

Then the frequency rises, and this indicates the age of your hearing, depending on when you stop hearing a certain sound.

So if you hear a frequency:

12,000 Hz - you are under 50 years old

15,000 Hz - you are under 40 years old

16,000 Hz - you are under 30 years old

17 000 – 18 000 – you are under 24 years old

19 000 – you are under 20 years old

If you want the test to be more accurate, you should set the video quality to 720p, or better 1080p, and listen with headphones.

Hearing test (video)

hearing loss

If you have heard all the sounds, you are most likely under 20 years old. The results depend on sensory receptors in your ear called hair cells which become damaged and degenerate over time.

This type of hearing loss is called sensorineural hearing loss. This disorder can be caused whole line infections, drugs and autoimmune diseases. The outer hair cells, which are tuned to pick up higher frequencies, usually die first, and so the effect of age-related hearing loss occurs, as demonstrated in this video.

Human hearing: interesting facts

1. Among healthy people frequency range that can be heard by the human ear ranges from 20 (lower than the lowest note on a piano) to 20,000 Hertz (higher than the highest note on a small flute). However, the upper limit of this range steadily decreases with age.

2. People talk to each other at a frequency of 200 to 8000 Hz, and the human ear is most sensitive to a frequency of 1000 - 3500 Hz

3. Sounds that are above the limit of human hearing are called ultrasound, and those below infrasound.

4. Our ears don't stop working even in sleep while continuing to hear sounds. However, our brain ignores them.

5. Sound travels at 344 meters per second. A sonic boom occurs when an object overcomes the speed of sound. Sound waves in front of and behind the object collide and create an impact.