The literature is replete of work on this; among others, a bunches of papers by Larry Summers and colleagues at Chuck’s university (Indiana) and another bunch by our ASA president elect Judy Dubno and her group will show you such correlation (it’s late and I am not going to give you the specifics, my excuses). However, the same folks and others (like my group) have shown that threshold elevation alone does not explain the loss of speech intelligibility in noise. Although you are young compared to some of us, you are now at the low end of the age range Larry, Judy, and I (and many others) have studied. In my lab, we tested over 200 over-60 folks with hearing loss not exceeding what is considered moderate and found pretty poor speech understanding in the majority of them, including those who had practically normal hearing. Unfortunately we have also seen that the loss of speech intelligibility in interference increases at a rate faster than the increase of hearing threshold.
From: "Richard F. Lyon" <dicklyon@xxxxxxx>
Reply-To: "Richard F. Lyon" <dicklyon@xxxxxxx>
Date: Thursday, October 31, 2013 at 11:20 AM
Subject: Re: National Hearing Test
What I'd like to understand better is exactly how the mechanisms causing threshold elevation also cause degradation of SNR threshold. I presume that the auditory filter bandwidths are wider, and the compression less, with hearing loss. But they're also wider at high levels, and high levels don't cause a degraded SNR threshold, do they? Or maybe they do, in normal hearing, at levels high enough to cause this much bandwidth widening?
I took the test just now and got the expected result: "slightly below normal range" in both ears (expected, based on previous tests that show somewhat worse than typical hearing for my 61-year age).
It would be great if there was better quantification of the result, like dB of SNR degradation relative to normal, rather than just "slightly below normal range". Charles, is there a numeric range associated with these words?It does seem like a pretty effective test of hearing in noise. I presume it's doing an adaptive SNR process, since it would usually give me a relatively easy one after each one where I was pretty much guessing.
I've definitely been feeling a degraded ability to deal with conversation in noisy environments (cafes and such), which I understand is correlated with absolute threshold elevation. I'm just not clear on why it's so correlated. Is it understood? Is there a good paper on this?
On Wed, Oct 30, 2013 at 9:02 AM, Watson, Charles S. <watson@xxxxxxxxxxx> wrote: