0

I am currently making an app that recognizes certain notes and chords and I have been scouting the internet to find really what happens when the computer records sound and I cant seem to find anything. I would really appreciate it if anyone can explain this process to me.

avi Amos
  • 1
  • 2
    I'm not sure this is exactly the right part of the stack exchange, might be worth trying https://engineering.stackexchange.com. But it depends on the file format, but would say looking at PCM (which is basically what a WAV file is) is a good place to start https://en.wikipedia.org/wiki/Pulse-code_modulation – ds4940 Nov 28 '19 at 10:45
  • 1
    audio from a mic is just a curve which wobbles just as the mic membrane or your eardrum ... this is time domain audio where in a plot you see height of this curve on Y axis with time on X axis , which is hard to use to identify notes or chords ... you can send this time domain audio into a fft call which is the same data yet in frequency domain ... here X axis is frequency and Y is intensity which lends itself to note or chord identification ... this is not a simple project yet very doable - good luck – Scott Stensland Nov 28 '19 at 15:06

1 Answers1

1

As mentioned in the comments, the computer is just recording the signal that is present on the microphone or instrument input that is being used. That signal is likely to be in a PCM / WAV format. The software you're using to record the sounds may choose to encode the audio to another format and/or preform some signal processing, before saving it to a file.

If you're inclined to write a little bit of code, plotting a spectrogram in Octave may be illuminating.

Kyle Krull
  • 1,618
  • 2
  • 18
  • 25