pbjbryan;205674 Wrote: > > Many sounds have asymmetric waveforms, especially voice, horns, and > percussion. The audibility of these signals can be affected by absolute > phase reversal if these sounds are prominent, and do not have any > reverb. > > Many years ago, I listened to a double blind demo of absolute phase > differences at an AES chapter meeting in one of the reference listening > rooms at Dolby lab's headquarters in SF. And for many sources, the > effect is not subtle. For others however, especially those with reverb > or ambience, the effect is unnoticable. >
Very interesting. Do you remember if any of the sources on which you could hear a difference were complex musical selections, or were they all tones or isolated sounds of some type? Most importantly, was it ever the case that one way sounded better - like an accurate reproduction of the original sound? Or did they just sound different? The only published work on this I've been able to find is http://www.aes.org/e-lib/browse.cfm?elib=6950 . They find that polarity is easily audible on special test tones (I've verified that, it's easy) but for normal music it's mostly inaudible. In fact the only acoustic sounds they identify for which the results are positive are solo piano and solo (acoustic) guitar, which is odd (since these actually have the most symmetric waveforms). For kick drum polarity wasn't audible in their experiment. They speculate that the audibility for the piano and guitar has something to do with transients, such as the initial phase of the sound. However that initial phase varies as you move in a circle around a guitar player, so one might expect that even if the effect is audible, it's not any more realistic one way than the other. -- opaqueice ------------------------------------------------------------------------ opaqueice's Profile: http://forums.slimdevices.com/member.php?userid=4234 View this thread: http://forums.slimdevices.com/showthread.php?t=35708 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
