On Sat, 3 Oct 2009 11:27:35 -0400, "Robert Green"
wrote:

I was at an elderly friend's house the other day when the smoke alarm went
off. It was quite loud and I reacted instantly to the noise. My friend, a
former Army marksman in his 70's, who's suffering from profound high
frequency hearing loss, heard nothing!!!

Then I started looking around for alarms that used lower frequency sounders
but the only thing I could find were specially converted smoke detectors
that cost $300!!!!

I'm wondering why COTS alarms operate at such a high sound frequency,
especially when it's well known that older adults lose their high frequency
hearing first. I have been thinking of just unsoldering the Sonalert
sounders in low priced alarms and replacing them with lower frequency
sounders, but that could compromise the detector's ability to sense smoke if
the replacement sounder has sufficiently different electrical
characteristics.

Does anyone know of a *reasonably* priced smoke detector whose sounder is
audible to people with high frequency hearing loss? I'd like to buy a
couple of such detectors for him, but the price on the only unit I've found
would bring the bill to over $1200 for four detectors, and that's just
unreasonable. I know what goes into making a smoke detector and 10x the
cost of the parts still wouldn't bring the price that high.

The idea that smokes use sounders that can't be heard by a lot of elderly
people seems pretty unreasonable to me as well.

Surely someone out there makes a smoke detector or combo smoke/CO detector
(even better) that makes a sound people with typical hearing loss could hear
a little better.

BTW, we can skip flashing light smoke detectors. BT, DT, GTS! He's got a
phone ringer/flasher that he never hears or sees. The unit's flasher can't
really be seen in daytime easily and the electronic ringer again uses a tone
in the 5000Hz and above range and is inaudible to him. FWIW, based on some
simple tests I did with CoolEdit, a PC program that allows you to create any
audible tone, he can hear most stuff below 4000Hz. Yes he has a hearing aid
but no, he does not sleep with it in.

Thanks in advance for your help.


The wired smoke detectors in my house are not high pitched at all and
I'm sure the builder didn't pay more then a small amount for them.
They make a loud buzzing sound, sort of like the emergency broadcast
sound you probably have heard on your TV and radio.