My father was complaining about not being able to hear high-pitched smoke alarms due to partial deafness, so I had a look on the RNID factsheet with a view to finding alternatives and it says
But why high-pitched? Wouldn’t something that emitted a loud low-pitch noise be just as effective?
Speaking as a normal-hearing person, loud low-pitched sounds (like, say, the bass line at a stadium concert in which you happen to be standing right in front of the speaker) grab your attention, but in a bone-thrumming kind of way that’s not that unpleasant. If I were asleep when the sound started - and I’m a heavy sleeper - I doubt I’d notice unless the bed were also shaking.
A high-pitched sound is absolutely painful on the ears though - have you never experienced a fire alarm up close? There’s a reason that “piercing screams” are invariably referred to as high-pitched!
A lot of fire alarms I’ve heard at schools and companies were intolerable for me. As in outright disorienting vomit inducing audio-horror. I don’t know who came up with one particular “screech-hiss-screech-whine” pattern combined with off-beat strobe lights but it felt like the 9th circle of techno hell. I’d love to know there is some justification for it other than being an effective emetic.
It made you want to leave the room. Mission accomplished.
ETA: They’re not supposed to be tolerable.
Lower pitches are omnidirectional. It is easier to determine the origin of a high pitched noise, which makes it easier to realise that the noise is coming from up on the ceiling where the smoke detector is.
Yes, but the problem is, I would guess that I have heard over a thousand smoke/fire alarms in my life and the number of those alarms that represented a real fire? Zero.
People have become so accustomed to the false alarms that they will sit through a real one until it’s too late, all the while bitching about the noise…
Being hearing-impaired, I cannot hear the super-high pitched smoke alarms unless I am in their immediate vicinity. This causes no end of consternation from my wife while I am cooking 
I would love a smoke alarm that emitted lower frequency noise. It doesn’t have to be a deep relaxing bass, just not super high pitched. Something along the lines of a low altitude cockpit alarm in aircraft. Those are loud, and DEFINITELY get your attention without sounding like a piezo-electric buzzer on steroids.
Things like ships’ klaxons are lower-frequency and they seem to grab attention just fine.
EXACTLY! If I could get a smoke/CO alarm that sounded like a ship’s klaxon I would be a happy camper. The coolness factor would be a plus.
Hence the arms race to make them less and less tolerable.
Mark my words, in twenty years, fire alarms will have to shoot out actual jets of fire before people will leave when they start.
Dunno how widespread they are, but at college they had the ones that not only had a high-pitched bell (BRRIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIING), but also a low-to-middling pitched buzzer (BRAAAAAAAAAAAAAAAAAAAAAAAAAAW). Maybe they’re covering all of their bases?
and thus ends my first attempt to find onomatopeoias which transcribe pitch
I don’t understand where you’re coming from? Are you saying fire alarms should just have a small LED, and no noise, so they’re easier to sit through?
As many of you have noted, there was no standard for many years. Bells, sirens, buzzers, and more could be used as audible fire alarm notifying signals.
From the National Fire Alarm Code, NFPA 72, 1999 edition:
The NFPA and other organizations continue to study the problem of emergency notification via audible means and their effectiveness on children, the elderly, and the hearing imparied, as well as the general public.
We had a fire in the lower level of my house in 2003 and I SLEPT through the fire alarm, which was on the ceiling in the hallway right outside of my open door…maybe they should all play “Reveille.”
The drivers (speakers) for higher frequencies are both smaller and more efficient. Both of these characteristics are desireable from a design and manufacturing POV.
To paraphrase Irish comedian Tommy Tiernan:
You could be sitting in a pub made of Christmas trees and petrol, in between a fireworks factory and a home for young criminals, and if the fire alarm went off, people would be sitting around making jokes about it: “Hahahaha. Is that my phone?!”
But they’re not desireable in this case!
They make fire alarms which include a bright strobe flash as well as a audio alarm, specifically for the hearing-impaired. I imagine there are similar smoke alarms available, if you want one.
They do, but if the smoke alarm is in the hallway, and I’m asleep in my bedroom, a strobe light won’t do much good.
It takes a big speaker and a lot of energy to produce a loud, low-pitched sound. Smoke alarms are small and most of them are powered by small batteries. I suppose it would be possible to make an alarm with a ten-inch woofer that would run off of household current, but most people wouldn’t want one like this.