At what distance can a person hear? Psychoacoustics and features of perception

We often evaluate sound quality. When choosing a microphone, audio processing program or audio file recording format, one of the most important issues- how good it will sound. But there are differences between the characteristics of sound that can be measured and those that can be heard.

Tone, timbre, octave.

The brain perceives sounds of certain frequencies. This is due to the peculiarities of the mechanism of the inner ear. Receptors located on the main membrane inner ear convert sound vibrations into electrical potentials that excite the auditory nerve fibers. The auditory nerve fibers have frequency selectivity due to the excitation of the cells of the organ of Corti located in different places main membrane: high frequencies are perceived near the oval window, low frequencies are perceived at the top of the spiral.

The physical characteristic of sound, frequency, is closely related to the pitch we perceive. Frequency is measured as a quantity full cycles sine wave in one second (hertz, Hz). This definition of frequency is based on the fact that a sine wave has exactly the same waveform. In real life, very few sounds have this property. However, any sound can be represented as a set of sinusoidal oscillations. We usually call this set a tone. That is, a tone is a signal of a certain height that has a discrete spectrum (musical sounds, vowel sounds of speech), in which the frequency of a sine wave is highlighted, which has the maximum amplitude in this set. A signal with a wide continuous spectrum, all frequency components of which have the same average intensity, is called white noise.

A gradual increase in the frequency of sound vibrations is perceived as a gradual change in tone from the lowest (bass) to the highest.

The degree of accuracy with which a person determines the pitch of a sound by ear depends on the acuity and training of his hearing. The human ear can clearly distinguish two tones that are close in pitch. For example, in the frequency range of approximately 2000 Hz, a person can distinguish between two tones that differ from each other in frequency by 3-6 Hz or even less.

The frequency spectrum of a musical instrument or voice contains a sequence of evenly spaced peaks - harmonics. They correspond to frequencies that are multiples of a certain base frequency, the most intense of the sine waves that make up sound.

The particular sound (timbre) of a musical instrument (voice) is associated with the relative amplitude of various harmonics, and the pitch perceived by a person most accurately conveys the base frequency. Timbre, being a subjective reflection of the perceived sound, has no quantitative assessment and is characterized only qualitatively.

In a “pure” tone there is only one frequency. Typically, the perceived sound consists of the frequency of the main tone and several “impurity” frequencies, called overtones. Overtones are multiples of the frequency of the main tone and are smaller in amplitude. The timbre of the sound depends on the distribution of intensity among the overtones. The spectrum of combinations of musical sounds, called a chord, depends on the distribution of intensity among the overtones. In such a spectrum there are several fundamental frequencies along with accompanying overtones.

If the frequency of one sound is exactly twice the frequency of another, the sound wave “fits” into one another. The frequency distance between such sounds is called an octave. The range of frequencies perceived by humans, 16-20,000 Hz, covers approximately ten to eleven octaves.

Amplitude of sound vibrations and volume.

The audible part of the sound range is divided into low-frequency sounds - up to 500 Hz, mid-frequency - 500-10,000 Hz and high-frequency - over 10,000 Hz. The ear is most sensitive to a relatively narrow range of mid-frequency sounds from 1000 to 4000 Hz. That is, sounds of the same strength in the mid-frequency range can be perceived as loud, but in the low-frequency or high-frequency range they can be perceived as quiet or not be heard at all. This feature of sound perception is due to the fact that the sound information necessary for human existence - speech or sounds of nature - is transmitted mainly in the mid-frequency range. Thus, loudness is not a physical parameter, but the intensity of the auditory sensation, a subjective characteristic of sound associated with the characteristics of our perception.

The auditory analyzer perceives an increase in the amplitude of the sound wave due to an increase in the amplitude of vibration of the main membrane of the inner ear and stimulation of an increasing number of hair cells with the transmission of electrical impulses with greater frequency and frequency. more nerve fibers.

Our ear can distinguish the intensity of sound in the range from the faintest whisper to the loudest noise, which approximately corresponds to an increase in the amplitude of movement of the main membrane by 1 million times. However, the ear interprets this enormous difference in sound amplitude as approximately a 10,000-fold change. That is, the intensity scale is strongly “compressed” by the mechanism of sound perception auditory analyzer. This allows a person to interpret differences in sound intensity over an extremely wide range.

Sound intensity is measured in decibels (dB) (1 bel is equal to ten times the amplitude). The same system is used to determine changes in volume.

For comparison, we can give an approximate level of intensity of different sounds: barely audible sound(hearing threshold) 0 dB; whisper near the ear 25-30 dB; average speech volume 60-70 dB; very loud speech (screaming) 90 dB; at rock and pop music concerts in the center of the hall 105-110 dB; next to an airliner taking off 120 dB.

The magnitude of the increment in the volume of the perceived sound has a discrimination threshold. The number of loudness gradations distinguished at medium frequencies does not exceed 250; at low and high frequencies it decreases sharply and averages about 150.

Everyone has seen such a volume parameter or one associated with it on audiograms or audio equipment. This is a unit of measurement for loudness. Once upon a time, people agreed and designated that a person normally hears from 0 dB, which actually means a certain sound pressure that is perceived by the ear. Statistics say that the normal range is either a slight drop of up to 20 dB, or hearing is above normal in the form of -10 dB! The delta of the “norm” is 30 dB, which is somehow quite a lot.

What is dynamic range of hearing? This is the ability to hear sounds at different volumes. It is usually accepted as fact that human ear can hear from 0dB to 120-140dB. It is highly recommended not to listen to sounds of 90 dB or higher for a long time.

The dynamic range of each ear tells us that at 0dB the ear hears well and in detail, at 50dB the ear hears well and in detail. It is possible at 100dB. In practice, everyone has been to a club or concert where the music was played loudly - and the detail was wonderful. We listened to the recording of food, barely quietly through headphones, while lying in quiet room- and also all the details are in place.

In fact, a decrease in hearing can be described as a reduction in dynamic range. In fact, a person with poor hearing cannot hear details at low volumes. Its dynamic range is narrowed. Instead of 130dB it becomes 50-80dB. That is why: there is no way to “shove” information that in reality is in the 130dB range into the 80dB range. And if we also remember that decibels are a nonlinear relationship, then the tragedy of the situation becomes clear.

But now let's remember good hearing. Here someone hears everything at a level of about 10 dB drop. This is normal and socially acceptable. In practice, such a person can hear normal speech from 10 meters away. But then a man appears with perfect pitch-- above 0 by 10 dB -- and he hears the same speech from 50 meters with equal conditions. The dynamic range is wider - there are more details and possibilities.

A wide dynamic range makes the brain work in a completely, qualitatively different way. There is much more information, it is much more accurate and detailed, because... more and more different overtones and harmonics are heard, which, with a narrow dynamic range disappear: escape a person’s attention, because impossible to hear them.

By the way, since a dynamic range of 100dB+ is available, this also means that a person can constantly use it. I just listened at a volume level of 70 dB, then suddenly started listening - 20 dB, then 100 dB. The transition should take minimal time. And in fact, we can say that a person with a decline does not allow himself to have a large dynamic range. Hard of hearing people seem to substitute the idea that everything is very loud now - and the ear is preparing to hear loud or very loud, instead of the real situation.

At the same time, the presence of dynamic range shows that the ear not only records sounds, but also adjusts to the current volume in order to hear everything well. The general loudness parameter is transmitted to the brain in the same way as sound signals.

But a person with perfect pitch can vary his dynamic range very flexibly. And in order to hear something, he doesn’t tense up, but simply relaxes. Thus, hearing remains excellent both in the dynamic range and at the same time in the frequency range.

Division of the audible range into three main groups

The terminology for dividing the audible frequency spectrum came to us partly from the musical world, partly from the scientific world, and in general it is familiar to almost everyone. The simplest and most understandable division that can test the frequency range of sound in general looks like this:

Low frequencies. The limits of the low frequency range are within 10 Hz (lower limit) - 200 Hz (upper limit). The lower limit begins precisely at 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 audible, and can also be felt tactilely in the case of deep low bass and even influence a person's psychological mood.
The low-frequency range of sound has the function of enrichment, emotional saturation and final response - if the dip in the low-frequency part of the acoustics or the original recording is strong, then this will not in any way affect the recognition of a particular composition, melody or voice, but the sound will be perceived as meager, depleted and mediocre, at the same time it will be subjectively sharper and sharper in terms of perception, since the mid and high frequencies will protrude and prevail against the background of the absence of a good rich bass region.

Enough large number musical instruments reproduce sounds in the low frequency range, including male vocals that can go down to 100 Hz. The most pronounced instrument that plays from the very beginning audible range(from 20 Hz) can easily be called a wind organ.
Mid frequencies. The boundaries of the mid frequency range are within 200 Hz (lower limit) - 2400 Hz (upper limit). The mid-range will always be fundamental, defining and actually form the basis of the sound or music of a composition, therefore its importance is difficult to overestimate.
This can be explained in different ways, but mainly this feature of human auditory perception is determined by evolution - it has happened over many years of our formation that the hearing aid most acutely and clearly captures the mid-frequency range, because within its borders is human speech, and it is the main tool for effective communication and survival. This also explains some nonlinearity of auditory perception, always aimed at the predominance of mid-frequencies when listening to music, because our hearing aid is most sensitive to this range, and also automatically adapts to it, as if “amplifying” it more against the background of other sounds.

The absolute majority of sounds, musical instruments or vocals are found in the middle range, even if a narrow range above or below is affected, the range still usually extends to the upper or lower middle. Accordingly, vocals (both male and female), as well as almost all well-known instruments, such as guitar and other strings, piano and other keyboards, wind instruments, etc., are located in the mid-frequency range.
High frequencies. The limits 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 extend into the region above 20 kHz, and as is known, overtones are ultimately responsible for the color of the sound and the final timbral perception of the overall sound picture. Seemingly “inaudible” ultrasonic frequencies can clearly influence a person’s psychological state, although they will not be audible in the usual manner. Otherwise, the role of high frequencies, again by analogy with low frequencies, is more enriching and complementary. Although the high-frequency range has a much greater influence 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 reach 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 more fully in sound they reach almost upper limit audible range (20 kHz) cymbals and violin.

In any case, the role of absolutely all frequencies of the range audible to the human ear is impressive and problems in the path at any frequency will most likely be clearly visible, especially to a trained hearing aid. The goal of reproducing high-precision sound of “hi-fi” class (or higher) is the reliable and maximally even sound of all frequencies with each other, as it happened at the time the phonogram was recorded in the studio. The presence of strong dips or peaks in the frequency response of the speaker system indicates that, due to its 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 the combination of sounds of instruments and voices, each of which sounds in some part of the frequency range. Some instruments may have a very narrow (limited) frequency range, while for others, on the contrary, it can literally extend from the lower to the upper audible limit. It must be taken into account that despite the same intensity of sounds at different frequency ranges, the human ear perceives these frequencies with different volumes, which is again due to the mechanism of the biological device hearing aid. The nature of this phenomenon is also largely explained by the biological need to adapt primarily to the mid-frequency sound range. So in practice, a sound with a frequency of 800 Hz at an intensity of 50 dB will be perceived subjectively by ear as louder compared to a sound of the same intensity, 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 is considered as a standard medium frequency 1000 Hz with a sensitivity of approximately 120 dB (may vary slightly depending on individual characteristics). As in the case of uneven intensity perception at different frequencies when normal levels loudness, approximately the same dependence is observed in relation to the pain threshold: it occurs most quickly at mid-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 135 dB. Pain threshold at low frequencies always higher than on medium and high ones.

A similar disparity is observed in relation to hearing threshold- this is the lower threshold after which sounds become audible to the human ear. Conventionally, the hearing threshold is considered to be 0 dB, but again it is valid for the reference frequency of 1000 Hz. If, for comparison, we take a low-frequency sound of 30 Hz, then it will become audible only at a wave radiation 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 level is raised. 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. However, a low-intensity sound that is too quiet will suffer from severe frequency unevenness due to biological features auditory perception, which is nonlinear 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 failure) of low and high frequencies. This problem has been well known for a long time; to combat it, a well-known function called tone compensation, which, through equalization, equalizes the levels of low and high frequencies close to the mid-level, thereby eliminating unwanted dip without the need to raise the volume level, making the audible frequency range of sound subjectively uniform in the degree of distribution of sound energy.

Taking into account the interesting and unique features of human hearing, it is useful to note that as the sound volume increases, the frequency nonlinearity curve levels out, and at approximately 80-85 dB (and above), sound frequencies will become subjectively equivalent in intensity (with a deviation of 3-5 dB). Although the leveling does not occur completely and a smoothed but curved line will still be visible on the graph, 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 resolved either with the help of an equalizer, or with the help of separate volume controls in systems with separate channel amplification.

Dividing the audible range into smaller subgroups

In addition to the generally accepted and well-known division into three general groups, sometimes there is a need to consider this or that narrow part in more detail and in detail, thereby dividing the frequency range of sound into even smaller “fragments”. Thanks to this, a more detailed division has appeared, using which you can quickly and quite accurately designate the expected segment of the sound range. Consider this division:

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

Upper Bass (80 Hz to 200 Hz) represented by the top notes of classical bass instruments, as well as the lowest audible frequencies of individual strings, such as a guitar. The upper bass range is responsible for the sensation of power and 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 bass 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 quickly and sharply, like a tangible tactile blow simultaneously with the direct perception of sound.

Therefore, it is the upper bass that is responsible for the attack, pressure and musical drive, and also only this narrow segment of the sound range is capable of giving the listener the feeling of the legendary “punch” (from the English punch - blow), when a powerful sound is perceived as tangible and with a strong blow in the chest. Thus, you can recognize a well-formed and correct fast upper bass in a music system by the high-quality development of an energetic rhythm, a collected attack and by the good design of instruments in the lower register of notes, such as cello, piano or wind instruments.

In audio systems, it is most advisable to give a segment of the upper bass range to midbass speakers with a fairly large diameter of 6.5"-10" and with good power indicators and a strong magnet. The approach is explained by the fact that it is the speakers of this configuration that will be able to fully reveal the energy potential inherent in this very demanding region of the audible range.
But don’t forget about the detail and intelligibility of sound; these parameters are just as 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, which will shape and build the scene. In the upper bass segment, stereo panorama can be heard perfectly, if it is provided for by the recording itself.

The upper bass area already covers enough large 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 take into account all instrument harmonics.

Lower mid (200 Hz to 500 Hz)- the most extensive area, covering most instruments and vocals, both male and female. Since the region of the lower mid range actually moves from the energetically saturated upper bass, we can say that it “takes over the baton” and is also responsible for the correct transmission of the rhythm section in conjunction with the drive, although this influence is already declining towards the pure mid range frequency

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. Also, it is 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 part 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 instruments.

Accordingly, the lower middle is responsible for correct design most instruments and voices, saturating the latter and making them recognizable by their timbre coloring. Also, the lower mids are extremely demanding with regard to the correct transmission of the full bass range, since it “picks up” the drive and attack of the main striking bass and is supposed to properly support it and smoothly “finish” it, gradually reducing it to nothing. The sensations of sound purity and bass intelligibility lie precisely in this area, and if there are problems in the lower middle due to excess or the presence of resonant frequencies, then the sound will tire the listener, it will be dirty and slightly booming.
If there is a shortage in the lower mids, then the correct feeling of the bass and the reliable transmission of the vocal part will suffer, which will be devoid of pressure and energy return. The same applies to most instruments, which without the support of the lower middle will lose “their face”, will become incorrectly shaped and their sound will noticeably become poorer, even if it remains recognizable, it will no longer be so complete.

When building an audio system, the range of the lower middle and above (up to the upper) is usually given to mid-frequency 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" or lower, but detail and the ability to reveal the nuances of sound are important, which is achieved by the design features of the speaker itself (diffuser, suspension and other characteristics).
Also, for the entire mid-frequency range, correct localization is vitally important, and literally the slightest tilt or rotation of the speaker can have a noticeable impact on the sound from the point of view of correct realistic recreation 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 capable of playing the lower range of the bass region, but others are added to them that start from the lower middle: cymbals (190-17000 Hz), oboe (247-15000 Hz), flute (240-17000 Hz), 14500 Hz), violin (200-17000 Hz). The indicated ranges take into account all instrument harmonics.

Mid mid (500 Hz to 1200 Hz) or simply a pure middle, almost according to the theory of equilibrium, this segment of the range can be considered fundamental and fundamental in sound and rightly called the “golden mean”. In the presented segment of the frequency range you can find the fundamental notes and harmonics of the absolute majority of instruments and voices. The clarity, intelligibility, brightness and shrillness of the sound depend on the saturation of the middle. We can say that the entire sound seems to “spread” to the sides from the base, which is the mid-frequency range.

If the middle fails, the sound becomes boring and inexpressive, loses its sonority and brightness, the vocals cease to bewitch and actually fade away. The middle is also responsible for the intelligibility of basic information coming from instruments and vocals (to a lesser extent, since consonant sounds are higher in the range), helping to distinguish them well by ear. Most existing instruments come to life in this range, becoming energetic, informative and tangible, and the same happens with vocals (especially female ones), which are filled with energy in the middle.

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

Upper mids (1200 Hz to 2400 Hz) represents a very delicate and demanding part of the range that must be handled with care and caution. In this area, there are not many fundamental notes that form the foundation of the sound of an instrument or voice, but a large number of overtones and harmonics, thanks to which the sound is colored, sharpened and bright character. By controlling this area of the frequency range, you can actually play with the color of the sound, making it either lively, sparkling, transparent and sharp; or, on the contrary, dry, 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 hurt the ears, irritate and even cause painful discomfort. Therefore, the upper middle requires a delicate and careful attitude, because Because of problems in this area, it is very easy to ruin the sound, or, on the contrary, to make it interesting and worthy. Typically, the color in the upper middle area largely determines the subjective genre of the speaker system.

Thanks to the upper middle, vocals and many instruments are finally formed, they become clearly distinguishable by ear and sound intelligibility appears. This is especially true for the nuances of reproducing the human voice, because it is in the upper middle that the spectrum of consonant sounds is placed and the vowels that appeared in the early ranges of the middle continue. In a general sense, the upper midrange favorably emphasizes and fully reveals those instruments or voices that are rich in upper harmonics and overtones. In particular, female vocals and many bowed, stringed and wind instruments are revealed truly vividly and naturally in the upper middle.

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

Low Treble (2400 Hz to 4800 Hz)- this is a zone/region of increased distortion, which, if present in the path, usually becomes noticeable in this particular segment. Also, the lower highs are flooded with various harmonics of instruments and vocals, which at the same time carry a very specific and important role in the final design of a musical image recreated artificially. The lower highs carry the main load of the high-frequency range. In the sound they manifest themselves mostly as residual and easily audible harmonics of vocals (mostly female) and persistent 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 distinguishing instruments and recognizing voices, although the lower upper remains an extremely informative and fundamental area. Essentially, these frequencies outline the musical images of instruments and vocals, they indicate their presence. If the lower high segment of the frequency range fails, the speech will become dry, lifeless and incomplete, approximately the same thing happens with instrumental parts - brightness is lost, the very essence of the sound source is distorted, it becomes clearly unfinished and under-formed.

In any normal audio system, the role of high frequencies is taken over by a separate speaker called a tweeter (high-frequency). Usually small in size, it is undemanding in terms of power input (within reasonable limits) similar to the middle and especially the low-end sections, 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 20,000 Hz. In the case of high-frequency speakers, almost by analogy with the midrange section, the correct physical location and directionality is very important, since 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 control the stage in many ways, bring performers closer/farther away, change the shape and presentation of instruments, play with the color of the sound and its brightness. As in the case of adjusting midrange speakers, the correct sound of tweeters is affected by almost everything, and often very, very sensitively: the rotation and tilt of the speaker, its vertical and horizontal location, distance from nearby surfaces, etc. However, the success of proper tuning and the finickiness of the HF section depends on the design of the speaker and its polar pattern.

Instruments that play to the lower treble do so primarily through harmonics rather than fundamental notes. Otherwise, in the lower-high range, almost all of the same ones “live” as were in the mid-frequency segment, i.e. almost all existing ones. The same goes for the voice, which is especially active in the lower high frequencies, with particular brightness and influence being heard in female vocal parts.

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

In fact, the presented segment of the range is comparable to increased clarity and detail of sound: if there is no dip in the mid-high, then the sound source is well localized mentally 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, compressed and synthetically unrealistic. Accordingly, regulation of the lower high frequency segment 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 effect of presence (or rather, they complete it in full, since the basis of the effect is deep and penetrating low frequencies), thanks to these frequencies the instruments and voice become as realistic and reliable as possible. We can also say about the mid-highs 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, in this part of the range the following are still active: 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), small flute (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 Treble (9600 Hz to 30000 Hz) a very complex and for many incomprehensible range, providing mostly support for certain instruments and vocals. The upper highs primarily provide the sound with characteristics of airiness, transparency, crystallineness, some sometimes subtle addition and coloring, which may seem insignificant and even inaudible to many people, but at the same time still carries a very definite and specific meaning. When trying to create a high-class “hi-fi” or even “hi-end” sound, the highest attention is paid to the upper high frequency range, 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 region of the upper highs, smoothly turning into ultrasonic frequencies, can still have some effect psychological impact: even if these sounds are not heard clearly, the waves are emitted into space and can be perceived by a person, moreover, at the level of 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, and sparkling aftertaste of music. If there is a lack of energy in the upper high range, it is quite possible to feel discomfort and musical understatement. In addition, the capricious upper treble range gives the listener a sense of spatial depth, as if being immersed deep into the stage and enveloping the sound. However, an excess of sound saturation in the designated narrow range can make the sound excessively “sandy” and unnaturally thin.

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

The idea behind 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 can be ignored in the musical path and, even if we do not hear them directly, they are still initially present during the live performance of a particular composition, which means they can indirectly have some influence. The situation with a super tweeter is complicated only by the fact that not all equipment (sound sources/players, amplifiers, etc.) are capable of outputting a signal in the full range, without cutting off frequencies from above. The same is true for the recording itself, which is often done with frequency range cutting and loss of quality.

The division of the audible frequency range into conventional segments in reality looks something like this described above; with the help of division, it is easier to understand problems in the sound path in order to eliminate them or to level out the sound. Despite the fact that each person imagines some exclusively his own and understandable only to him standard image of sound in accordance only with his own taste preferences, the nature of the original sound tends to balance, or rather to the averaging of 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 obtain the most even and balanced sound, without peaks and dips throughout the entire audible range. Such a sound may seem boring and inexpressive in nature to the average inexperienced listener, lacking brightness and of no interest, but it is precisely this sound that is truly correct in fact, striving for balance by analogy with how the laws of the universe itself in which we live manifest themselves .

One way or another, the desire to recreate a certain sound character within the framework of one’s audio system lies entirely on the preferences of the listener himself. Some people like a sound with a predominance of powerful lows, others like the increased brightness of “raised” highs, others can spend hours enjoying the harsh vocals emphasized in the middle... There can be different perception options huge variety, and information about the frequency division of the range into conventional 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 the laws to which sound as a physical phenomenon is subject.

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 setup of any audio system and make it possible to build a stage in principle, but will also provide invaluable experience in assessing the specific nature of the sound. With experience, a person will be able to instantly identify sound defects by ear, and, moreover, very accurately describe the problems in a certain part of the range and make assumptions possible solution to improve the sound picture. Sound adjustments can be made various methods, where you can use an equalizer as “levers,” for example, or “play” with the location and direction of the speakers - thereby changing the character early reflections waves, eliminating standing waves, etc. This will be a “completely different story” and a topic for separate articles.

Frequency range of the human voice in musical terminology

The human voice plays a separate and distinct role in music as a vocal part, because the nature of this phenomenon is truly amazing. The human voice is so multifaceted and its range (compared to musical instruments) the widest, with the exception of some instruments, such as the piano.
Moreover, in different ages a person can make sounds of different pitches, 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 voices in the range of 5 octaves!

Children's

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

Men's

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

Women's

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

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

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

The frequency then increases and this indicates the age of your hearing based on when you stop hearing a particular 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 yet 1080p, and listen with headphones.

Hearing test (video)

Hearing loss

If you heard all the sounds, you are most likely under 20 years old. 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 may be caused by a whole series infections, medications and autoimmune diseases. The outer hair cells, which are tuned to detect higher frequencies, are usually the first to die, causing the effects of age-related hearing loss, as demonstrated in this video.

Human hearing: interesting facts

1. Among healthy people frequency range that the human ear can detect 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 decreases steadily with age.

2. People talk to each other at a frequency from 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 audibility are called ultrasound, and those below - infrasound.

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

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

6. Ears - self-cleaning organ. The pores in the ear canal secrete earwax, and tiny hairs called cilia push wax out of the ear

7. The sound of a baby crying is approximately 115 dB, and it's louder than a car horn.

8. In Africa there is a Maaban tribe who live in such silence that even in old age they hear whispers up to 300 meters away.

9. Level bulldozer sound idling is about 85 dB (decibels), which can cause hearing damage after just one 8-hour day.

10. Sitting in front speakers at a rock concert, you're exposing yourself to 120 dB, which begins to damage your hearing after just 7.5 minutes.

Human hearing
Hearing- the ability of biological organisms to perceive sounds with their hearing organs; special function hearing aid, excited sound vibrations environment, such as air or water. One of the biological distant sensations, also called acoustic perception. Provided by the auditory sensory system.
Human hearing is capable of hearing sound ranging from 16 Hz to 22 kHz when vibrations are transmitted through air, and up to 220 kHz when sound is transmitted through the bones of the skull. These waves have an important biological significance, For example, sound waves in the range of 300-4000 Hz correspond to the human voice. Sounds above 20,000 Hz have little practical significance, as they slow down quickly; vibrations below 60 Hz are perceived through the vibration sense. The range of frequencies that a person is able to hear is called the auditory or sound range; higher frequencies are called ultrasound, and lower frequencies are called infrasound.
The ability to distinguish sound frequencies greatly depends on the individual: his age, gender, heredity, susceptibility to hearing diseases, training and hearing fatigue. Some people are able to perceive sounds of relatively high frequencies - up to 22 kHz, and possibly higher.
In humans, like in most mammals, the organ of hearing is the ear. In a number of animals, auditory perception is carried out thanks to a combination various organs, which can differ significantly in structure from the ear of mammals. Some animals are able to perceive acoustic vibrations without audible by humans(ultrasound or infrasound). Bats During flight, they use ultrasound for echolocation. Dogs are able to hear ultrasound, which is what silent whistles work on. 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.

Mechanism of operation auditory system:
A sound signal of any nature can be described by a certain set of physical characteristics:
frequency, intensity, duration, time structure, spectrum, etc.
They correspond to certain subjective sensations that arise when the auditory system perceives sounds: volume, pitch, timbre, beats, consonance-dissonance, masking, localization-stereo effect, etc.
Auditory sensations are associated with physical characteristics ambiguous and nonlinear, for example, volume depends on the intensity of the sound, its frequency, spectrum, etc. Back in the last century, Fechner’s law was established, confirming that this relationship is nonlinear: “Sensations
are proportional to the ratio of the logarithms of the stimulus." For example, sensations of a change in volume are primarily associated with a change in the logarithm of intensity, height - with a change in the logarithm of frequency, etc.
He recognizes all the sound information that a person receives from the outside world (it makes up approximately 25% of the total) with the help of the auditory system and the work of the higher parts of the brain, translates it into the world of his sensations, and makes decisions on how to react to it.
Before we begin to study the problem of how the auditory system perceives pitch, let us briefly dwell on the mechanism of operation of the auditory system.
Many new and very interesting results have now been obtained in this direction.
The auditory system is a kind of receiver of information and consists of the peripheral part and higher parts of the auditory system. The processes of transformation of sound signals in the peripheral part of the auditory analyzer have been most studied.
Peripheral part
This is an acoustic antenna that receives, localizes, focuses and amplifies the sound signal;
- microphone;
- frequency and time analyzer;
- an analog-to-digital converter that converts an analog signal into binary nerve impulses - electrical discharges.
A general view of the peripheral auditory system is shown in the first figure. Typically, the peripheral auditory system is divided into three parts: external, middle, and inner ear.
Outer ear consists of the pinna and the auditory canal, ending in a thin membrane called the eardrum.
The external ears and head are components of an external acoustic antenna that connects (matches) the eardrum to the external sound field.
The main functions of the external ears are binaural (spatial) perception, sound source localization, and amplification of sound energy, especially in the mid- and high-frequency regions.
Auditory canal It is a curved cylindrical tube 22.5 mm long, which has a first resonant frequency of about 2.6 kHz, so in this frequency range it significantly amplifies the sound signal, and this is where the region of maximum hearing sensitivity is located.
Eardrum - a thin film 74 microns thick, has the shape of a cone, with its tip facing the middle ear.
At low frequencies it moves like a piston, at higher frequencies it forms a complex system of nodal lines, which is also important for amplifying the sound.
Middle ear- air-filled cavity connected to the nasopharynx eustachian tube for leveling atmospheric pressure.
When atmospheric pressure changes, air can enter or leave the middle ear, so the eardrum does not respond to slow changes in static pressure - descent and ascent, etc. There are three small auditory ossicles in the middle ear:
malleus, incus and stapes.
The hammer is attached to eardrum one end, the other it comes into contact with the anvil, which is connected to the stapes with the help of a small ligament. The base of the stapes is connected to oval window into the inner ear.
Middle ear performs the following functions:
matching the impedance of the air environment with the liquid environment of the cochlea of the inner ear; protection from loud sounds(acoustic reflex); amplification (lever mechanism), due to which the sound pressure transmitted to the inner ear is amplified by almost 38 dB compared to that which hits the eardrum.
Inner ear located in a labyrinth of canals in temporal bone, and includes the organ of balance ( vestibular apparatus) and a snail.
Snail(cochlea) plays a major role in auditory perception. It is a tube of variable cross-section, coiled three times like a snake's tail. When unfolded, it is 3.5 cm long. Inside, the snail is extremely complex structure. Along its entire length it is divided by two membranes into three cavities: scala vestibule, median cavity and scala tympani.
The transformation of mechanical vibrations of the membrane into discrete electrical impulses of nerve fibers occurs in the organ of Corti. When the basilar membrane vibrates, the cilia on the hair cells bend and this generates an electrical potential, which causes electrical currents to flow. nerve impulses, carrying all the necessary information about the received sound signal to the brain for further processing and response.
The higher parts of the auditory system (including the auditory cortex) can be considered as a logical processor that identifies (decodes) useful sound signals against a background of noise, groups them according to certain characteristics, compares them with images in memory, determines their information value and makes decisions about response actions.