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Old 07-13-2018, 05:07 PM
MichaelEmouse MichaelEmouse is online now
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How many beats per second can human hearing distinguish?

Let's say I play the same sound several times per second at equidistant intervals. How many times can I play it per second until I'm no longer able to distinguish that they're discrete sounds and they start blending together?

Second, if I were to analyse the sound I play, would I find that it only seems continuous because it's composed of its own repetitions which are too rapid for me to resolve? Is it turtles all the way down?
Old 07-13-2018, 05:21 PM
engineer_comp_geek's Avatar
engineer_comp_geek engineer_comp_geek is offline
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The human brain seems to top out at both vision and sound somewhere around 1/10th to 1/15th of a second, with a bit of variation between individuals. Sounds that occur less than 1/15th of a second apart seem simultaneous, just as images that change faster than 1/15th of a second seem like motion and not individual images.

TV and movies use a slightly faster frame rate than that since even though 10 to 15 frames per second is "good enough" for most people, your brain still perceives a bit of flicker. Getting up above 30 frames per second gets rid of the flicker.

Similarly, at about 10 to 15 beats per second, your sounds will blend together.

I don't understand your second question.
Old 07-13-2018, 05:42 PM
Ignotus Ignotus is offline
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I know precious little about acoustics or phonology; but I believe you would benefit from reading the works of Herrman von Helmholtz, who actually made these things a science.
Old 07-13-2018, 06:40 PM
DPRK DPRK is offline
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Humans can usually hear sounds between about 20-20000 Hz, so once in that range you should be hearing a distinct pitch; the record, under ideal laboratory conditions, for hearing a musical tone is 12 Hz. There is also a phenomenon called temporal masking where a strong sound causes you not to perceive a weaker sound for a short time before (20 ms) or after (up to 200 ms) it.

If you analyse an arbitrary sound sample, for example with a Fourier transform, it is true that it is composed of a spectrum of frequencies, but it is subject to complicated psychoacoustics when you hear it. But, yes, physically you can regard it as a combination of repetitive sine waves.


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