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Re: hearing aid question: "boominess"
This is a common problem, and the causes are summarized in
Kuk, F. and Ludvigsen, M.S. (2002) "Amplcusion management 101: Understanding variables," Hearing Review 9(8).
In general, the problem is due to the fact that the level of the wearer's own voice at their TM is higher than the typical level of other people's voices. Frequencies below 1kHz in the person's own speech can be 15 dB higher than those frequencies from others' speech at the wearer's ear. If the aid is set to properly amplify other people's speech and is unable to properly change its gain when the spectrum changes due to the wearer starting to speak, then improper amplification is applied and the user will complain about the sound quality of their own voice. In general, this is true of other sounds too--hearing aids need to constantly adjust their gain in a frequency dependent manner to accurately amplify all sounds, and getting gains, compression ratios, time constants, etc optimized for a specific patient is a challenge.
----- Original Message -----
From: "Richard H." <auditory@xxxxxxxxxxxxxx>
Subject: hearing aid question: "boominess"
Date: Mon, 2 May 2005 17:03:18 +0100
> Hi team,
> I am a newly qualified dispenser and need a bit of advice please.
> I am dispensing a digital hearing aid and the patient reports an unpleasant
> "echo" or "boominess".
> This is NOT occlusion. After a lot of trials I can make the boominess go away
> by dropping gain in a notch around 1kHz.
> However this also reduces speech volume & intelligibility!
> The loss is 40dB flattish, and I am using WDRC with 55-60dB TK point.
> This is driving me nuts ... is there anything obvious I should be looking at
> for causes of "boominess"?
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