Re: 'pressure at the ears' visiting an anechoic chamber

[Jen Tufts <jbt2@xxxxxxx>]

Dear List,
        If Jont/Cyril's explanation is correct, perhaps that also explains
the similar feeling of pressure experienced when one enters a much quieter
(but not sound-isolated) environment after having been exposed to loud sound
for a long period of time (temporary threshold shift may be greater for high
frequencies than lows).  A couple of questions related to the 'unlearning'
of this sensation:  do people with a substantial hearing loss, esp in the
higher frequencies, experience the same pressure sensation upon entering a
sound-isolated room, and do workers who are routinely exposed to loud sounds
experience a pressure sensation when they leave the work environment?

Jennifer Tufts

 At 03:29 AM 10/28/98 +0000, Jont Allen wrote:
>Dear List,
>I have been doing some "research" about this pressure effect in the ears,
>when you enter the anechoic chamber (AC). I called Cyril Harris, and asked
>him for his opinion on this effect. He had to think about it, and didn't
>have an answer of the top of his head, but he came up with a reasonable
>explanation, I think.
>
>When you have pressure on your ears, there is lots of static (low frequency)
>pressure relative to high frequencies. He suggests that when you walk into
>the AC, the high frequencies are damped, but not so much for the lows.
>Thus the spectral balance is tilted heavily toward the low frequencies.
>It is, he argues, the strong low frequency bias towards the low end of
>the spectrum that gives the "pressure effect," just as in the case of
>normal high frequencies with a static pressure.
>
>What do you think of this explanation?
>
>Jont Allen/Cyril Harris

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