On 10/06/2010 4:19 AM, Doug Freyburger wrote:
> gloria.p wrote:
>>
>> Have you attended a lot of rock concerts? Do you play the radio loudly
>> in the car? Mow with a gas mower and no ear protection? Use a chain
>> saw? Lots of loud noise or just aging can affect your high frequency
>> hearing range. You may not be impaired for normal conversation and
>> still not be able to hear high frequency sounds.
>
> My ex played the stereo at levels that caused me pain. Just one of the
> several ways she was abusive. I wasted a lot of time trying to solve
> the problem before leaving her.
>
> For years I've noticed filtering problems. I've had hearing tests where
> they close my in a quiet sound-proofed room and played quiet noises.
> Heck, in that environment I can here my own heart beating so I don't
> show hearing loss except like those cell phone rings for young kids.
>
> I've never yet seen a hearing test where they put you in a car on the
> interstate driving next to an 18-wheeler and then try to talk to you.
> If your lips are in my peripheral vision I might see them move and
> notice but the words won't pierce the background noise at all. We like
> to drive around sight seeing. When my MIL was still alive I would watch
> my wife and her from the back seat. One set of lips would move. Then
> the other would reply. No sound at all pierced the background noise for
> me yet it was completely clear neighter of them was lip reading. The
> difference in filtering is amazing.
>
> My health insurance company put out an article on the two types of
> hearing loss a couple of months ago. It's the first I've ever read
> about the filtering but I've experienced it for years before the divorce
> long before I met my good wife.

One or two points of note here. Most of the intelligibility in speech
comes from the higher frequencies. It is those frequencies that enable
you to make out the complex range of sounds in the spoken word. As well,
the broad spectrum of frequencies enable us to discriminate between
different voices enabling us to follow one conversation in a room full
of people talking yet able to exclude others.

As the high frequency loss extends down into the speech range,
difficulties begin to emerge. Women voices, having higher frequencies
than men, become difficult to understand first.

If you want to know what this is like, think of AM radio compared to FM.
AM radio, because of the way it was transmitted, had no frequencies
above 5,000 Hz. FM went much higher than this. Because of this fact
alone, it was much easier to misunderstand what was said on AM than on
FM radio broadcasts, hence the push to FM.

What you are finding is that background noise is at the exact same set
of frequencies as the voices and you no longer have the broad frequency
spectrum which enables you to discriminate.

Krypsis