Comment Re: And 1...2...3... (Score 1) 433
human audio dynamic range is at least 120 dB.
Yes, if you want to hear a mosquito and a jackhammer at the same time. Not sure what music you're listening to, but I'm sure glad I'm not your neighbour.
both I and a friend of mine found places with so-called ultrasonic alarms painful.
That doesn't mean you are hearing ultrasonics - there are modulation effects and other audible frequencies that are generated by 'ultrasonic' transducers that are produced as well as the ultrasonics. It's certainly quite a claim to suggest that you could year 27kHz signals - what was generating them?