The Hearing Man

Fundamentals of perception In hearing humans, two essential aspects always meet: the physiology of hearing the psychology of hearing Hearing physiology comprises the frequency bandwidth and the dynamic range of the auditory system as well as the conduction of nerve impulses to the brain. Auditory psychology comprises the determined auditory experiences and their relationship to life situations. The entire auditory perception is essentially determined by the genetic, the natural and the social determination of the individual. Humans always perceive natural sound events, such as music, on the basis of their individual determination, in natura as well as in reproduction. The result is always a sense of hearing. What we lack when listening to reproduced music is the reference for what information is actually on the recordings. Thus our auditory perception is always subject to a listening expectation. When we hear an original sound event, e.g. the transient of a guitar string, we hear a certain signal structure. We hear this signal structure with all the physiological and psychological characteristics of our sense of hearing. This results in our auditory impression of the original. If we want to perceive a reproduction exactly like the original, then the reproduced sound structure must (!) be identical with the original sound structure, so that we have the same hearing result with all physiological and psychological characteristics of our hearing sense. The reproduction must not carry any assumptions of hearing-physiological or hearing-psychological peculiarities, because twice hearing-physiological and hearing-psychological influences in succession are absurd and illogical and can never lead to the same hearing impression as the original. In addition, there is the fact that we perceive many things unconsciously. Although we can no longer consciously articulate that we are hearing something, we do so nonetheless. Logically, the unconscious perception is not reflected in our consciousness. We believe that we do not perceive anything, but we do it anyway. And these unconscious perceptions are processed in the same way, e.g. on the emotional level, the unconscious thinking. Some feelings, however, are consciously perceived and thus perceptions reach consciousness in part by a detour. Therefore, the following applies to the technical reproduction of sound events and the faithful perception of the original: If fast processes / high frequencies are present in the original in a certain intensity, they must be reproduced in the same intensity so that the event is perceived by the listener as being the same as the original. For example, when a person hears a sitar in the original, the original spectrum of the instrument passes through the individual human perception like a filter. Original - filter - auditory impression. When a human hears the reproduction of a sitar, the process of perception is the same. To arrive at the same auditory impression, the reproduced sitar must be identical to the original Star. Reproduction - filter - auditory impression. Any form of limiting the spectrum of the instrument during reproduction would inevitably lead to a hearing impression different from the original. Our perception is ultimately a model. There are limits, exclusions, experiences and assumptions, and the vital aspect of error compensation. The more a sound event, e.g. the voice of someone we know, is superimposed by extraneous sounds, the more intensively we fall back on our memory on the basis of the recognized "sound fragments". We thus assemble the sound character of what we remember with what we really hear. A subjective inner reconstruction. Because of the unconsciousness of the process, we believe we hear the voice of the person or the shattering glass better than is actually the case. Since there is quite a large collective intersection of experiences, at least within a cultural group, the subjective error compensations also lead to similar results or judgments. Thus, a group of subjects may arrive at similar judgments. The exciting thing about this is that the greater the alienation, the more all participants fall back on their respective subjective memories (collective intersection). What we are actually missing is the information of reality: the real sound of the voice, the real characteristics of the shattering glass. On the subject of proper transformation, what is available to us as the original is the recording of the original. We know from our own experience that recordings (productions) can be very good or very bad. Again, the more compressed, filtered, limited, etc., the more intensely we compensate ourselves on the basis of memories. Comb filter effects and locatability absurdities due to off-center placement in stereophonic playback with equal right-left portions and a superimposed, time-delayed, structurally altered reflection mix complicate perception. What halfway saves us again are the "sound fragments", the residual information of the original. The most usable are those of reflections, at least of similar reflections of unaffected direct sound components. When measuring loudspeakers with transient signals - impulse, sine half-wave and also with the jump - we see how short the time window of such direct sound components is (depending on the distance of reflecting objects / surfaces). We see the original waveform unaffected by reflections only within the first milliseconds. This is the period of the definition of the transients. If we want to know something about reality or about its recording, the transients are our lifeline within a "sound field chaos".

Myro Spirit IV

Hearing types People can be divided into three hearing types according to their preferences. What is important in differentiating the types is that every physically and mentally healthy person carries the perceptual patterns of all three types. That which establishes an assignment to a hearing type is its preference in perception. It is also important to remember that there is a range of variation in each person. This is dependent on many factors such as hunger, stress, breathing, well-being, etc. Therefore, we prefer the music that suits us in the most different states / moods. The "pressure hearing type" or "tonal hearing type" The main points are: the sound pressure the pitch the slow perception the steady tone low to medium tones Sensory perception of pressure is one of the simplest forms of perception possible even in simple life forms. Being able to detect the frequency of pressure fluctuations, to recognize and remember pitch in the brain is an extension of this perceptual ability. Dynamics, in particular, are perceived as the difference between the mean of loud passages and the mean of quiet passages. Pressure listeners feel a sense of well-being only when bass sound waves stimulate the inner abdomen. They feel overwhelmed by too much information and too fast processes. This is often accompanied by a limited perception of spatiality. Acoustic information does not trigger a three-dimensional pictorial image in the brain of a not inconsiderable part of the population. Corresponding qualities of music transmission chains are therefore not or hardly perceived. This group of people perceives corresponding qualities or deficiencies rather as clarity or obfuscation. Access to phenomena of three-dimensionality, on the other hand, remains denied. Acoustic localization is limited to the localization of the origin of the sound, i.e. whether it comes from the left or the right or from the middle or from below or above. This applies to the actual origin, e.g. from a loudspeaker or a reflection from a wall. Dipole loudspeakers or loudspeakers with rear drivers (usually tweeters) are here an aid to the perception of spatial depth, since the localization of the rear reflections are substitutes for the missing three-dimensional image in the brain.

The "Rhythm Hearing Type" or "Analytical Hearing Type" The main focuses are: fast rhythmic structures impulse dynamics energy analytics medium to medium-high tones A more complex and faster perception is required when it comes to impulse dynamics and complex vibration patterns. Fast analytical abilities are demanded of the brain here.

The "structural hearing type" or "sensual hearing type" The focal points are: Micro-structures Fine dynamics spatial perception frequency bandwidth high and low tones This hearing type possesses the distinctive characteristics of visualization and spatial perception. The ability to perceive extremely fast processes and highly complex structures is also one of its characteristics.

In the type theory of Ayurveda, the different auditory sensations are expressed thus: If the Pitta type is completely taken in by the analytically jagged playing, the Kapha type gets malaise and the Vata type lacks breadth. When the kapha type bathes in heavy, calm sounds and gets excited by the pressure, the pitta type gets bored and the vata type gets restless and jittery. When the Vata type revels in sound spaces, the Pitta type becomes aggressive and the Kapha type lacks gut feeling. And this is exactly how one could evaluate the sound descriptions of different people who all get to hear the same music. What appeals emotionally to one, leaves the other cold.

Myro Rebel 3

Phase sensitivity of hearing Phase is probably the most difficult phenomenon in acoustics to explain. On the other hand, the effect of phase behavior, or the different time delays of different frequencies, on natural sounds is easily audible to everyone - yet even experts often have as much difficulty explaining the issue as laypeople have understanding it. To illustrate the phenomenon of different phase behaviors, the best analogy is to optical perception: the image of a distorting mirror vividly illustrates the effect of strong phase shifts and thus time-shifted sound reproduction across frequencies. Most loudspeakers divide the audible frequency range into two or three sub-ranges, for the transmission of which specialised transducers - woofers, mid-range drivers and tweeters - are responsible. The transducers must produce the sound at the same time and in the same place, otherwise the original harmonic structure is lost. Linear phase response means that a loudspeaker presents the same time delay for all frequencies in the audible frequency range. Only then can it reproduce natural sounds without compromise. The Myro frequency filters meet this condition. When discussing the audibility of metrological differentiations, such as the phase or the step response, we must first ask ourselves whether it is an inherently audible aspect at all. The same applies to the combination of, for example, phase and amplitude. The question whether we can hear the phase is thus easily answered. A frequency response in itself is not an audible event. A phase response in itself is also not an audible event. Phase is just a construct of a measurement model. We hear pressure fluctuations within the medium of air. But the phase does not include sound amplitude values! One must always deal with sound structures. All other measurement models lack essential parameters for hearing. We hear pressure-time curves - nothing else. We hear a sound pressure structure. When we discuss whether we hear phase shifts, we need to think about what the sound pressure structure resulting from a phase shift looks like, or what effect a phase shift has on the sound pressure structure. Whatever is used to shift the acoustic phase while keeping the frequency response constant, it changes the sound structure. The sound pressure amplitude values contained in the constant frequency response are temporally restructured by phase shifts. So it is not only the phase that changes and therefore no conclusions can be drawn about the audibility of phase shifts.

Phase shifts of continuous tones are inaudible because there are no references to other sound events. Phase shifts of certain sound components within a complex sound structure, on the other hand, are very audible. The audibility of amplitude frequency responses that are as linear as possible cannot be discussed in isolation, because we do not hear sound amplitude values per se. A sound pressure value is a constant. In contrast, we hear sound amplitude value 'changes' within a sound structure.
Phase sensitivity, and thus also the detection of errors in the phase response, differs depending on the frequency range. In the sensitive hearing range, we also perceive phase shifts more sensitively. At low frequencies, due to the wavelengths, the phenomenon occurs that phase shifts in the transmission of a sound (frequency mixture) pull the fundamental and overtones extremely apart in time, because 45° phase shift for low tones corresponds to a much longer time than for high tones with their short wavelengths.

The auditory sense reacts:

• very sensitive to phase shifts in the transient (especially in natural sound events).
• sensitive to phase shifts within sounds
• insensitive to phase shifts of isolated transient tones

When we talk about the audibility of measurement results, we can consequently only talk about complex sound events. All other statements are merely abstract subjective ideas about how one or another measured value might affect hearing. Pure speculation! Nobody will claim to be able to deduce the sound structure in his head from the frequency response and the group delay. Step responses are complex sound events. We hear differences in step responses just as we can distinguish the cracking of twigs or the clapping of hands. These are all very short sound pressure structures that we can clearly distinguish. We can even hear the different sound characters. This is clear for anyone to confirm from natural auditory experience. And what is true for step responses is also true for all sound structures used as test signals, such as a sine period or a sine burst etc.. They are all directly audible.

Hearing thresholds The term auditory threshold suggests a certain magnitude of perceptual intensity which, if fallen below, is associated with loss of recognition of what is perceived. This gives rise to the interpretation or impression of can you hear or can you not hear. In discussions about hearing thresholds, there is always a tendency to regard a nameable value as a fixed limit. But a person does not hear up to e.g. 16 kHz. There is a reduction in the intensity of perception. It means that then e.g. 18 kHz are perceived only more quietly. However, the hearing ability of people is to an extremely high degree individual! There are no generally definable hearing thresholds. Hearing thresholds occur in relation to minimum volume levels and in relation to masking effects. However, neither of these apply to transients in particular. They are the loudest vibrations, i.e. the first to be perceived, and they are the sound vibrations that trigger masking effects in the first place. By the way, in healthy hearing organs the masking effects are much less pronounced than in not fully functional hearing organs. The definition of hearing thresholds is based on the statistical evaluation of numerous hearing tests. The hearing threshold is not defined as the value that can be reached by at least one person, but rather the results of many hearing tests are combined to form a statistical value. Therefore, there are not only people whose perception already ends above a hearing threshold, but many people can also still hear signals below the general hearing threshold. A hearing threshold is not an absolute limit! The variability of a hearing threshold is particularly illustrative when listening to high frequencies. Whereas young people can clearly hear transient sounds up to over 20 kHz, i.e. they have a very high hearing threshold, the audibility of older people ends at 14 kHz or below. What value can therefore be defined as a general hearing threshold? There is no value that does justice to every person and describes their hearing ability. Each person has a very individual hearing profile and even this is not constant, but depends on countless factors. Hearing thresholds are defined in a statistical sense under previously defined model conditions. Factors to be considered include: the type / choice of stimulus Is it a transient or a quasi-static condition? the purity of the stimulus the reproduction quality of the sound generator the position of the subjects in relation to the sound generator the room acoustic conditions in the case of headphones: the position, the fit of the headphones the mental/psychological framework conditions of the model test the time of the model test (time of day, season) the age and physical conditions of the test persons the communication ability and speed of the test persons the individual range of the scattering of results etc. In other words: We hear differently in the morning than in the evening, differently when blood flow and quality are optimal than when they are deficient. Under stress or mental manipulation, by e.g. a test situation, we hear differently than in a completely relaxed state. In addition, there is the current physiological state of the auditory system: Are the auditory canals clear or clogged with all kinds of debris? Are the sinuses clear or do they create pressure on the auditory canal? What is the blood pressure and pulse? Can you hear a murmur in the blood vessels or even tinnitus noises? Are there vertebral misalignments, tension in the neck and throat muscles?

Myro Time 1'

In the swing-in, the results are quite different due to the approximately 30 times (!) higher nerve firing rate associated with it, i.e. associated with maximally heightened sensory perception. And this enumeration could be continued infinitely. Listening experiences with short-time stimuli and the listening impressions of various seminar and workshop participants confirm the clear audibility of sound characteristics, especially with short-time stimuli. The hearing sensitivity of transient signals, on the other hand, is considerably lower! The fact that different stimuli produce the same auditory impression is incorrect due to the dynamic reaction and adaptation of the auditory system, especially to dynamic processes. Even in steady states, one can at most speak of a similarity. The fact that polarity differences are audible with functional monitoring equipment can thus be confirmed.

Example: If we listen to a continuous sine wave and add X percent distortion, it will result in a certain subjective hearing threshold. This is different for each person! But if we consider when and how loud or quiet continuous tones (e.g. the decay of a guitar string) are contained in the complex music signal, then the statements about the hearing thresholds determined on continuous tones become completely relative. These are different for each person anyway. A generalized statement about this has only paper value, is pure statistics, determined in some test under very specific conditions and therefore only under these conditions of statistical value. Nothing more.

But this is completely meaningless for the correct conversion of a loudspeaker! It does not matter for a transducer, whether it is a DA-converter or an electro-acoustic transducer, how the subjective listening process of one of the many billions of people takes place. Transducers, like all technical apparatus, are designed to perform specific tasks; they fulfill a role imposed by definition. A DA converter is supposed to reconstruct an original analog signal structure from zeros and ones. An electroacoustic transducer is supposed to convert an electrical signal structure fed to it into an equivalent sound structure. This is the only way to provide our auditory organ with a sound structure that is as close to reality as possible. What each individual then makes of it in his brain, that is up to each person.

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