3 ms·

Great article. I want to weigh in about this whole perceivable jitter thing. I think it’s important when making music related programming decisions to recogni

Great article. I want to weigh in about this whole perceivable jitter thing. I think it’s important when making music related programming decisions to recognize there’s a whole area of perception in between actually conscious “hey that metronome is off!” and actually being imperceptible. In that area the feel and impact of music can be altered while no one can pinpoint why. For safety’s sake I think sub-millisecond timing in controllers and things like metronomes needs to be the standard. The ideal should be audio rate accuracy, when it can be reasonably achieved. It’s really bad to fall in the trap of thinking that just because no one can point out a problem, it isn’t having an effect. Especially with audio where people have trouble explaining what they are hearing.

jwandborg 7y ago
Keep in mind that the testing methodology may have already accounted for your concerns. I would guesstimate that mechanical vinyl and tape players have rate variations on the order of milliseconds.
- whiddershins 7y ago
  Good point, but jitter is within a phrase, speeding something up and down smoothly would be entirely different than discontinuous random timing variation. I am not sure exactly what the tests and methodologies are that different people refer to, but I do know that when I have brought up this concern to instrument and software developers who are operating at the cutting edge of this stuff and really should know the answer, they never bother to debate it until you get to the difference between sub-millisecond and audio-rate. It is axiomatic that anything that has less resolution than audio rate can be perceived, under the correct circumstances. For example, if you had two metronomes which each played the same wide-frequency burst and had independent jitters on their start time, the combined sound would likely shift in timbre due to the phase relationship of the summed waves. If you had those two outputs going to a stereo output, one on the left channel, and one on the right, the resulting effect should be that the "click" will randomly pan around the soundfield in the listener's perception. So, I guess it also depends on not only your use case but how much of a hassle it is to get the right resolution. I would be really sad if I subtly messed up some musician's sense of time for years in the future because they were practicing diligently with some jittery metronome I made.
human20190310 7y ago
> In that area the feel and impact of music can be altered while no one can pinpoint why. This has happened to me on many occasions. Having a part that needs to be in-the-pocket accidentally shifted (due to MIDI latency on weird gear or bad sample editing) just throws everything off in a way that's really hard to even identify.

jwandborg 7y ago

Keep in mind that the testing methodology may have already accounted for your concerns. I would guesstimate that mechanical vinyl and tape players have rate variations on the order of milliseconds.

whiddershins 7y ago
Good point, but jitter is within a phrase, speeding something up and down smoothly would be entirely different than discontinuous random timing variation. I am not sure exactly what the tests and methodologies are that different people refer to, but I do know that when I have brought up this concern to instrument and software developers who are operating at the cutting edge of this stuff and really should know the answer, they never bother to debate it until you get to the difference between sub-millisecond and audio-rate. It is axiomatic that anything that has less resolution than audio rate can be perceived, under the correct circumstances. For example, if you had two metronomes which each played the same wide-frequency burst and had independent jitters on their start time, the combined sound would likely shift in timbre due to the phase relationship of the summed waves. If you had those two outputs going to a stereo output, one on the left channel, and one on the right, the resulting effect should be that the "click" will randomly pan around the soundfield in the listener's perception. So, I guess it also depends on not only your use case but how much of a hassle it is to get the right resolution. I would be really sad if I subtly messed up some musician's sense of time for years in the future because they were practicing diligently with some jittery metronome I made.

human20190310 7y ago

> In that area the feel and impact of music can be altered while no one can pinpoint why. This has happened to me on many occasions. Having a part that needs to be in-the-pocket accidentally shifted (due to MIDI latency on weird gear or bad sample editing) just throws everything off in a way that's really hard to even identify.