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dcrowe
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Distortion in the Ear

I have been doing some reading (for example at http://deposit.ddb.de/cgi-bin/dokserv?idn=972885544&dok_var=d1&dok_ext=pdf&filename=972885544.pdf) that indicates the nonlinear distortion products generated within the ear have been recorded for analysis. This would seem to imply that the ultimate limits to audio fidelity occur within the ear itself. I have been aware for some years of distortions that I hear in common among all playback systems no matter which system I am listening to. (I can only detect this with recordings that I know well, and I have not been able to hear it in live performance.) I have thought that this may represent the residual distortion level within my own ears. It is difficult to find data on distortion in normal hearing, since most work is intended to help those with hearing loss, but there is experimental evidence that significant levels of distortion are generated within the nonlinearities of normal (undamaged) hearing. This motivates the development of direct nerve interface electronics that avoid the nonlinear mechanical cochlear interface! That is one answer to another thread on "The Future of Loudpeakers", namely: no speaker at all!

ohfourohnine
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Re: Distortion in the Ear

You have to help me with this one. You have detected distortion on many different sytems when playing recordings that you know well. It is a kind of distortion you don't hear when listening to live performances. Nontheless, you believe the distortion exists in your ears? Obviously I didn't understand you.

dcrowe
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Re: Distortion in the Ear


Quote:
You have to help me with this one. You have detected distortion on many different sytems when playing recordings that you know well. It is a kind of distortion you don't hear when listening to live performances. Nontheless, you believe the distortion exists in your ears? Obviously I didn't understand you.

I understand your question. I am saying that I may hear distortion in my ears, but the particular distortion product that I speculate could be occuring in my ear is so subtle that I am only sure I hear it when listening to musical material that I have heard repeatedly. I am not therefore sure that it is distortion in the ear. But it occurs with every system, unlike many other distortions that vary from system to system. It is possible then that it is on the reording.

This is all very peripheral to the main point that publications claim that distortion has been detected within the mechanical linkage in the ear. Whether or not we can tell which distortion component it is while listening, we are told that it does exist.

I am reminded of a listening session with Alan Hill and his Plasma Speakers in his Albuquerque home. He sold these commercially at one time, but they were very expensive and they require that you periodically refill the gas supply. Alan made the comment that any distortion you would hear while istening to these speakers occurs in the ear itself. I did hear some distortion.

Kal Rubinson
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Re: Distortion in the Ear

"This is all very peripheral to the main point that publications claim that distortion has been detected within the mechanical linkage in the ear. Whether or not we can tell which distortion component it is while listening, we are told that it does exist."

It is doubtful that anyone can perceive that 'distortion' since one has no reference for it. That it can be measured electrophysiologically does not mean it is rightfully comparable to external electronic distortion or mechanical distortion or to internal problems like tinnitus.

Kal

Monty
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Re: Distortion in the Ear

This reminds me of the stories of people who suddenly began to hear radio broadcasts through the braces in their teeth.
Probably an urban legend, but I recall hearing several stories over the years regarding this.

Perhaps there could be some sort of RFI noise that you detect.

dcrowe
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Re: Distortion in the Ear


Quote:
"This is all very peripheral to the main point that publications claim that distortion has been detected within the mechanical linkage in the ear. Whether or not we can tell which distortion component it is while listening, we are told that it does exist."

It is doubtful that anyone can perceive that 'distortion' since one has no reference for it. That it can be measured electrophysiologically does not mean it is rightfully comparable to external electronic distortion or mechanical distortion or to internal problems like tinnitus.

Kal

This is an interesting point: What does distortion mean? If it means departure from the way that sound is perceived by the healthy ear, then yes the physiological "distortion" is part of that normal process, and is not a departure. As a purely hypotehtical gedanken experiment, it is interesting to wonder how music would sound fed by a microphone and electronics (through an appropriate set of nerve impulse encoders) directly to the brain. Perhaps it would strike us as "distorted" because the nonlinear cochlear products are missing! This, even though these products would be termed distortion if produced in a playback system. At some time in the future when high fidelity restoration of nerve deafness becomes possible, it may be necessary to introduce nonlinearities if the sound is to seem entirely "natural." There may arise controversy if a switch is included that allows the user to compare "natural" to "undistorted" sound.

dcrowe
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Re: Distortion in the Ear


Quote:
This reminds me of the stories of people who suddenly began to hear radio broadcasts through the braces in their teeth.
Probably an urban legend, but I recall hearing several stories over the years regarding this.

Perhaps there could be some sort of RFI noise that you detect.

I have heard the urban legend, and it is possible that a tooth filling could act as a rectifier (radio detector). However, the resulting audio signal is not encoded into the nerve pulses that are sent by the ear, and the nerve in the tooth does not feed the part of the brain associated with hearing. Unless the audio signal causes something in the head to vibrate and create sound that is then heard (it would be very faint!) I do not see a mechanism for this to work.

Kal Rubinson
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Re: Distortion in the Ear

It may be semantic. Any transform that loses or adds information can be defined as distortion or, alternatively, as enhancement. Intent and perspective make the difference.

Kal

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