Most of us would go to great lengths to protect our expensive audio gear from the vagaries of commercial voltages, dust etc...but having read a few chapters of Master Handbook of ACOUSTICS by F. Alton Everest, I would like to restate what we have known all along..the most crucial link in the audio chain are our ears..(though unlike stuff for which we have to render financial accountability according to economic systems that are not under our immediate control or comprehension, the ear..at least your first pair is for free)
in a nut shell, this book which as you would expect for a tome of this scope, just touches cursorily on the biology of hearing.. but that sketchy info was, at least for me, enough to start 'seeing' my ear in a new light..
the ear basically comprises of the outer ear, the middle ear and the inner ear..not to mention the brain which actually hears things..
out of the three 'zones' the first two are quite well understood ..
the outer ear, of which the protruding pinna is a conspicuous part, is the vibration gathering device, a kind of a catchment for vibrations ("the external ears are no mere crinkly decorations but complex channels or convolutions which add a slight, reflected sound or echo to any sound that one hears...This slight, added echo will vary with the different angles from which sounds originate. For example, if one hears a sound above , the tiny echo added by the ears crinkles will differ from the one that they add to a sound coming from below or to one from behind .
Now, this minute echo will enter the ear a fraction of a second after the main sound does. Then that part of the brain that cares for ones hearing will analyze this main sound and its accompanying delayed echo. And by this analysis one is immediately made aware of the direction from which the sound came. So quickly does all this take place that one is not even conscious of it. Further, when one hears a sound coming from the right, then the right ear hears it just before the left ear does and vice versa. This too plays a part in the ability to know the direction from which a sound originates)
- in a sense the ear affixes directionality to the sound from a vibrational perspective..as the book says 'the direction of sound of the sound is superimposed on the sound content itself'..
(an experiment: if we listen with one ear to random noise..a 7.2kHz noise seems to come from a source at level to the ear, an 8kHz noise seems to come from above and 6.3kHz from below..which means the directional information is extracted from the sound spectrum itself)
the ear canal, to which the sonic information (be it your wife's rant or a sublime Parker's Mood is conveyed as variations in air pressure) is another marvel..acoustically the middle ear is comparable with a pipe organ of 2.5cm length and .7cm diameter..which means that the air that is trapped in it resonates for frequencies of about 3000Hz..thus making the ear most sensitive to midrange frequency where most of the relevant sound information resides...(in addition to this, when sound wave hits the face it gets diffracted, this diffraction also increases the sound pressure at the mid frequencies)
the middle ear:
this comprises of a liquid..hence the air vibrations of the ear canal have to be transferred into the vibrations of the liquid..(the middle ear also has a hot line to the outer atmospheric pressure via the Eustachian tube, which also function as a drainage when the middle ear gets infected)..the sound vibrations in the air of the ear canal vibrate the ear drums which initiate the action of the ossicles -the three bone lever arrangement comprising of the incus, mallus and stapes- a mechanical impedence device that renders an optimal transfer of vibration from the air medium to the liquid of the middle ear...
note:
the ears have built-in protection against extremely loud noises. Though, a sudden nearby explosion can result in excessive vibrations that could cause irreparable damage to the intricate hearing apparatus. But if a very loud sound develops gradually, quick-acting muscles can turn down the volume. The eardrums membrane is tightened to reduce its vibrations, and middle-ear muscles twist the auditory ossicles. Thus the stirrup does not transmit such great vibrations through the oval window into the inner ear.
the inner ear...this is the business end of the ear where it gets complicated for the novice..though one may want to look up Georg von Bksy
on wiki...along with the problem of how the workings of the organ of Corti visa vi its communication with the brain...
after this it gets complicated so will expect the experts to carry from here..
moral of the story: take good care of the ears, it is more complicated, ingenious and intricate than you could possible imagine...at least I couldn't...
imagine that is...i can still hear though..
in a nut shell, this book which as you would expect for a tome of this scope, just touches cursorily on the biology of hearing.. but that sketchy info was, at least for me, enough to start 'seeing' my ear in a new light..
the ear basically comprises of the outer ear, the middle ear and the inner ear..not to mention the brain which actually hears things..
out of the three 'zones' the first two are quite well understood ..
the outer ear, of which the protruding pinna is a conspicuous part, is the vibration gathering device, a kind of a catchment for vibrations ("the external ears are no mere crinkly decorations but complex channels or convolutions which add a slight, reflected sound or echo to any sound that one hears...This slight, added echo will vary with the different angles from which sounds originate. For example, if one hears a sound above , the tiny echo added by the ears crinkles will differ from the one that they add to a sound coming from below or to one from behind .
Now, this minute echo will enter the ear a fraction of a second after the main sound does. Then that part of the brain that cares for ones hearing will analyze this main sound and its accompanying delayed echo. And by this analysis one is immediately made aware of the direction from which the sound came. So quickly does all this take place that one is not even conscious of it. Further, when one hears a sound coming from the right, then the right ear hears it just before the left ear does and vice versa. This too plays a part in the ability to know the direction from which a sound originates)
- in a sense the ear affixes directionality to the sound from a vibrational perspective..as the book says 'the direction of sound of the sound is superimposed on the sound content itself'..
(an experiment: if we listen with one ear to random noise..a 7.2kHz noise seems to come from a source at level to the ear, an 8kHz noise seems to come from above and 6.3kHz from below..which means the directional information is extracted from the sound spectrum itself)
the ear canal, to which the sonic information (be it your wife's rant or a sublime Parker's Mood is conveyed as variations in air pressure) is another marvel..acoustically the middle ear is comparable with a pipe organ of 2.5cm length and .7cm diameter..which means that the air that is trapped in it resonates for frequencies of about 3000Hz..thus making the ear most sensitive to midrange frequency where most of the relevant sound information resides...(in addition to this, when sound wave hits the face it gets diffracted, this diffraction also increases the sound pressure at the mid frequencies)
the middle ear:
this comprises of a liquid..hence the air vibrations of the ear canal have to be transferred into the vibrations of the liquid..(the middle ear also has a hot line to the outer atmospheric pressure via the Eustachian tube, which also function as a drainage when the middle ear gets infected)..the sound vibrations in the air of the ear canal vibrate the ear drums which initiate the action of the ossicles -the three bone lever arrangement comprising of the incus, mallus and stapes- a mechanical impedence device that renders an optimal transfer of vibration from the air medium to the liquid of the middle ear...
note:
the ears have built-in protection against extremely loud noises. Though, a sudden nearby explosion can result in excessive vibrations that could cause irreparable damage to the intricate hearing apparatus. But if a very loud sound develops gradually, quick-acting muscles can turn down the volume. The eardrums membrane is tightened to reduce its vibrations, and middle-ear muscles twist the auditory ossicles. Thus the stirrup does not transmit such great vibrations through the oval window into the inner ear.
the inner ear...this is the business end of the ear where it gets complicated for the novice..though one may want to look up Georg von Bksy
on wiki...along with the problem of how the workings of the organ of Corti visa vi its communication with the brain...
after this it gets complicated so will expect the experts to carry from here..
moral of the story: take good care of the ears, it is more complicated, ingenious and intricate than you could possible imagine...at least I couldn't...
imagine that is...i can still hear though..
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