How does delay-based pitch-shift work?


    Dec 20 2011 | 2:28 am
    Hey! I guess this is a quite easy question since the technique exists pretty long: I want to build a pitch-shifter based on delay. How does it work? I assume folloeing:
    - building a tape-delay (which changes pitch when delay-time is changed)
    - sawtooth modulation of delay-time
    Anything useful about my guess? Please help! Thank you!

    • Dec 20 2011 | 3:05 am
      yep you're on the right track-- it's also related to the doppler effect, when an approaching sound-source's apparent pitch increases (it's delay time decreases because sound takes less time to reach the listener), and vice-versa
    • Dec 20 2011 | 8:34 am
      Hi
      as the delayed repeats 'move further away' (ie, delay time increases) the period of the frequencies increases, creating the illusion of a fall in pitch and vice versa. It's obvious how this works in the real world, but perceptually? I haven't a clue! There's a great example of how to achieve this effect in MaxMSP on youtube, with helpful explanations of relevant formulae etc, by 'dude837'
      Brendan
    • Dec 20 2011 | 9:26 am
      There's a good explanation in Puckette's book, which you can view free at:
      http://crca.ucsd.edu/~msp/techniques.htm
      There's a PD example, which is fairly easy to translate into Max here:
      http://crca.ucsd.edu/~msp/techniques/latest/book-html/node125.html
      and the explanation here:
      http://crca.ucsd.edu/~msp/techniques/latest/book-html/node115.html
      You can ignore the maths, and still get the gist of it!
      Cheers
      Roger
    • Dec 20 2011 | 6:35 pm
      Thank you, everyone!
    • Dec 21 2011 | 2:48 am
      Just one fact which actually made me think about all that:
      In an interview MOUSE ON MARS say "These are two delays which run into feedback quickly. And with the speed of the feedback-rate you can control the pitch." - This really confused me. :)
    • Dec 21 2011 | 4:19 pm
      on mars physics are different.