"G. Morgan" wrote in message

stuff snipped

Robert,

That issue has been addressed by the NFPA. See he
http://www.hearinglossweb.com/tech/alrt/smoke/code.htm

Thanks. I knew the problem was bad, but apparently as many as 70 million
Americans having high-frequency hearing loss, according to that site.
That's a pretty big chunk of people to leave out of the design process.
Maybe there was a patent issue involved.

I never thought about the problem until I was standing next to someone who
couldn't hear a peep of what I thought was ear-drum damaging loud, but then
again, I don't design smoke detectors. I'm glad that after 20 or 30 years
worth of sales, something's finally being done to address the problem as
indicated by the URL you posted.

I'd still like to find 3 or 4 battery powered smokes or combo smoke/CO's
that don't need hardwiring and don't cost more than $50 each. Hopefully
someone can tell me for sure which brands make that lower frequency
squarewave 520Hz sound that's being mandated.

It sounds like I need to keep my fingers crossed until the new models come
out and hope that he doesn't burn himself up before then . . . naw . . .
couldn't live with myself if something bad happened in the mean time. I'll
keep looking. At least I have a new search term: 520Hz. I expect that to
help a lot in finding what I am looking for. Thanks again for the URL.
(time passes) - not as helpful as I thought. It seems only two alarm makers
have such units, and they're way overpriced compared to traditional battery
detectors. And I mean waaaaay over. I can get 10 normal alarms for the
price of one of the specialized low frequency units. If there's anything I
hate, it's gouging the sick and disabled. This is a perfect example. Smoke
detectors, as the new rules make clear, should be able to wake most people
up, not just one demographic.

--
Bobby G.