[PD-ot] how low (latency) can you go?

[Hans-Christoph Steiner]

On Dec 18, 2006, at 4:59 AM, IOhannes m zmoelnig wrote:

> Hans-Christoph Steiner wrote:
>>
>> Honestly, I doubt you could tell the difference between 4ms and  
>> 14ms in
>> a blind test.  There have been many studies on this.  If you can  
>> detect
>> such tiny differences in onset time, you would be superhuman.
>>
>> For a tonal sound like a piano, humans perceive two sounds as one if
>> they have an onset within 30ms of each other.  Humans can perceive  
>> such
>> tiny temporal details, but this is for timbral perception rather than
>> onset perception.
>>
>> So my guess as to what is happening is that you can recognize the
>> differences and it is something that has been deemed a source of
>> annoyance.  But when it comes down to it, all of the studies I  
>> have seen
>> clearly show that musicians can perform equally at latencies  
>> around 50ms
>> versus much lower latencies.
>
> people can perform equally, but they have to do this consciously.  
> which
> is a problem, because they will fatigue more quickly.
>
> obviously there are instruments and instruments when it comes to  
> latency.
> violinist probably don't have much of a problem, but instruments  
> with a
> hard attack are more likely to have.
> additionally, instruments where the sound is the only feedback you  
> get,
> are heavily depending on low latencies.
> for example (i think i bring this example every time we discuss on
> this), we had a clarinetist here, who did not play clarinet but a
> wind-controller (a midi-box with a mouth-piece), controlling some
> hardware synthesizers. he is used to playing this instrument.
>
> he keeps telling me (i just met him 3 days ago), that it was a pain to
> play with our pd-based system (which just _added_ another 15-25ms
> (cannot remember; it was not _very low_ though) to hist breath->midi
> converter latency, and hist hardware synth latency).
>
> he gradually became louder in order to minimize the latency (with
> physical wind instruments this helps), and after 1 hour of playing he
> almost collapsed (ok, that's a bit exaggerated)

I don't doubt that it was fatiguing to play that instrument.  But do  
you have any specific data that shows that the latency was the source  
of the problem?  My guess is that the reduction of feedback is  
essential part of this.  I think that a system with so little  
feedback will be fatiguing to play no matter how low the latency.

Back when I was a trumpetter, when playing a MIDI trumpet, the first  
and dominant thing I noticed was the feeling of numbness.  I was used  
to a lot of physical feedback in my mouth and lips, but there was  
much, much less with the MIDI trumpet (no vibrating lips in the  
mouthpiece).  I don't recall noticing  latency at all.

Physical feedback has a much quicker feedback loop, and perhaps more  
importantly, a much lower cognitive load.  In order to compensate for  
the lack of physical feedback, you have to put a lot of effort into  
focusing the auditory processing parts of the brain on smaller  
details on a smaller timescale than usual, and that would be  
undoubtedly fatiguing.  Normally, the clarinetist would have lots of  
physical feedback, so the auditory portions of the brain can be  
focused more on a higher timescale.

.hc





>
> m,gsdft
> IOhannes
>
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