Is 4kHz too high a beeper frequency?

Either way, I think Win's original 4kHz is probably OK and the ear is sensitive there unless the person is deaf at that frequency which could definitly be the case for a lot of people. I'm luck so far but getting older and lower HF response fer sure.

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coupling to the air. The acoustic or mechanical coupling can be done in a way that makes the coupling more efficient giving more volume for the same power.

t

ower the resonant frequency of a small piezo and at the same time increase the efficiency. I wasn't criticizing any product.

I think that's the problem. It is much more likely for people to have prob lems hearing 4 kHz than 2 or 1 kHz. We have people reporting here that the y have trouble hearing 4 kHz. If you can't hear 2 kHz well you are definit ely in the "hard of hearing" department as it will impact your ability to h ear speech, particularly female voices, and so likely have hearing aides. For hearing loss at 4 kHz not so much.

I remember being able to hear the 15 kHz flyback transformers in TV sets. That was a long time ago.

--

  Rick C. 

  +-- Get 1,000 miles of free Supercharging 
  +-- Tesla referral code - https://ts.la/richard11209

Same here. Towards the end of my days repairing TVs, I had to rely on an assistant to keep a listening watch for the hiss.

I think I might have damaged my hearing while working on diesel generators for the power agency in the '80s. I didn't work on the engines but the associated electricals and electronics had to be tested with a running engine.

I can still detect sound in the low to mid frequencies as well as a much younger person. It's loss of the harmonics that sometimes makes me fail to catch what someone is saying.

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** You just wont give up with that misconception.

It is not common to have lost most or all hearing at 4kHz unless you are 80 or 90 years old.

Average 70 year olds can hear up to 11kHz.

FYI average 20 year old females can here 22kHz.

Audio has been my MY life long business - obviously it was never yours.

You stupid plonker.

..... Phil

Absolutely nothing you said contradicts what he said. It is mind boggling that you can't understand that.

Do you understand the meaning of, "a lot", "common", "most" and "average"? If you did you would know that even if everything you said is true, what Bob said can also be true.

Leave the guy alone and go back to your soldering iron.

--

  Rick C. 

  +-+ Get 1,000 miles of free Supercharging 
  +-+ Tesla referral code - https://ts.la/richard11209

A severe notch in my hearing was one of the medical 4F ratings I was giv en when I registered for the draft at 18 years old. The draft board doctor said that because of where it was in the audio spectrum, "It could get you killed on the battlefield." I had four more 4F ratings and was told that I could never serve. They drafted me, two years later.

If they used square waves localization is much easier for most users.

Greg

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** Nonsenese.

Localisation difficulty is caused by massive room echoes.

Plus the third harmonic at 12kHz is the only audible one, so useless to anyone over 60.

.... Phil

Phil is contradicting himself.

So at 60 no one hears 12 kHz but at 70 the average person hears 11 kHz??? Between 60 and 70 most people's hearing limit is stable to 1 kHz between 11 kHz and 12 kHz???

I guess if you consider "average" means whatever Phil wants it to mean.

But this guy is the expert according to so many.

I really like this one... no matter what Phil thinks of it.

--

  Rick C. 

  ---- Get 1,000 miles of free Supercharging 
  ---- Tesla referral code - https://ts.la/richard11209

Phil Allison wrote in news: snipped-for-privacy@googlegroups.com:

Plus square wave input to such an audio transducer rarely get produced as a true square. Things get rounded. Same with sawtooth. The transducer simply cannot respond that fast and the mechanical response itself gets damped a bit.

I have a tuning app on my ipad that generates the full range of musical notes in various waveform shapes. It is really cool and one of the few apps I actually paid for the fool version of and I am not even a musician, other than my likes and I can sing. Great app, if you want to choose a good tone.

But the cheap piezos are resonant ceramic slabs.

--

John Larkin         Highland Technology, Inc 

Science teaches us to doubt. 

  Claude Bernard

=======================================

** The capacitive load of a piezo element means current flow is proportional to applied frequency. So squarewave drive means odd harmonics have the same current as the fundamental.

The famous piezo tweeter has strong output to well beyond the audio band for this reason - up to 40 kHz in some examples.

.... Phil

Phil Allison wrote in news: snipped-for-privacy@googlegroups.com:

You should still check out the tuning applet. Especially if you play an instrument or sing.

** ????

Phil Allison wrote in news:d1ef40c8-4430-46cb- snipped-for-privacy@googlegroups.com:

In my original response was a link...

** I'm still no wiser about what your idea is.

.... Phil

Phil Allison wrote in news: snipped-for-privacy@googlegroups.com:

You can use it to generate a tone, you can use it to tell you what any local tone is oscillating at. VERY accurately.

It can be used to tune your instruments and your voice. It also has a nice metronome in there.

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** I have microphones, frequency counters, sine/square wave generators and scopes that do that too plus a good guitar tuner.

But I do not have a smart phone.

Horrible things.

..... Phil

I have one and have had several but I never use them. I either give them away or resell them. Friends and family keep urging me to use them and I can see where they can be useful. But seeing so many people letting the damned things dictate their lives turns me off.

I used a Nokia C2-01 for a long time. Nice little thing but it was stolen, after which I fell back on my ancient Nokia 1100. It serves well enough for receiving text and confirmation calls from banks and companies that accept only mobile phone numbers.

I have a landline phone in my home office and others around the house, plus a Panasonic cordless phone.