On 2006-12-16 20:44:22, Hans-Christoph Steiner hans@eds.org appears to have written:
On Dec 16, 2006, at 1:14 PM, Bryan Jurish wrote:
On 2006-12-16 19:02:08, Hans-Christoph Steiner hans@eds.org appears to have written:
And always, when talking about latency, I feel the need to point out the speed of sound: 340 m/s or .34 m/ms. So if your speakers are 2m away from you, that's 6ms of latency. You could spend days tweaking your machine to get 3ms less latency, or you could move 1m closer to your speakers. Puts things into perspective...
indeed 'tis true. but 5ms vs. 10ms makes a major subjective/perceptual difference if we're talking about playing an electro-acoustic instrument in and getting a munged signal out...
Do you have any references on that? I think it could be perseptable to a very experienced musician, but I don't think there is a major effect.
well, i wouldn't call myself a *very* experienced musician, but plugging a guitar into the computer and just running the signal through a simple [adc~]->[dac~] in pd with 10ms reported latency (latency.pd gives 10-11ms) is easily detectable, it being a pain in the wazoo to play (probably has to do with the fact that i am at best only a mediocre guitarist, but that's not the point :-/). also, 10ms is roughly the minimal "willed action -> muscular implementation" latency on your average homo sapiens architecture (get a stopwatch, try it out ;-)
From the studies that I have read, jitter has a much larger affect than latency in terms of affecting performance. (I need to find some references myself... ;)
i think you're right there. i know Reinhold Kliegl and Ralf-Thomas Krampe have done a lot of rhythm perception studies in Potsdam, with professional musicians, amateur musicians, and non-musicians as subjects, and the pros pretty much blew everyone else away precision-wise.
Performers are actually quite adept at adjusting to latency. Just think of an orchestra or choir: there could be 20ms or more of latency from one side of the stage to the other, yet its not hard
for > a moderately trained group to handle it.
as a former orchestra inmate myself, i seem to recall concentrating mostly on keeping a constant time myself -- the "big picture" ("big sound?") just isn't available to a 3rd tier 2nd violinist -- i went by the conductor's tempo and the momentum i got from those around me: the only real trick was keeping it constant, but that's "just" training: hence perhaps the jitter-related problems even for the pros...
Another key factor in performance is physical feedback, which has a much faster feedback loop that the audio system. Trained musicians can feel a mistake and correct it long before the sounds are consciously perceived. (I first saw that in print on one of Miller's papers http://crca.ucsd.edu/~msp/Publications/icmc93.ps)
One realm were I could see that latency would be important would be when measuring response time to a stimulus, like in a psychological experiment. But even still, as long as the latency is steady (i.e. low jitter), the latency is not a big deal.
it can certainly be compensated for if it is known, but for me as a guitarist, it amounts essentially to learning an entirely new style, since i'm just plain not good enough to compensate before the glitches become painfully audible...
marmosets, Bryan