4 ms·
That's a nice estimation, but I would have imagined direction is down to whether a sound is more muffled or quiet in one ear than the other.
by smcl 5y ago
That's a nice estimation, but I would have imagined direction is down to whether a sound is more muffled or quiet in one ear than the other.
- Griffinsauce 5y agoThat doesn't need to be the case when there are reflections.
- smcl 5y agoI'm not sure I follow
- jacquesm 5y agoA reflection can easily be louder than the original sound, but the longer time-of-flight allows the ear to distinguish between the two. That's how even in a hall with echoing walls you can still pinpoint a soundsource with relatively high accuracy.
- datameta 5y agoThe first chapter of The Sound Book by Trevor Cox goes into great detail about this (but without getting deep into the math of it). Well worth the read for those interested in the acoustics of architecture and our perception of how it modifies the soundscape.
- jacquesm 5y agoAnother interesting one is 'the acoustical foundations of music'. ISBN 0393090965
- whiddershins 5y agoNo it is difference in phase.
- jacquesm 5y agoOnly for LF.
- vitus 5y agoTo piggyback on the sibling comments: If you only determined direction based on relative volume between your ears, you wouldn't be able to distinguish between sounds in front vs behind you.
- smcl 5y agoYep that's why I added "muffled" (i.e. not 100% clear). Maybe it's worth clarifying that I wasn't trying to correct the commenter, just adding my original (naive? wrong?) belief about how this worked :)
- Ensorceled 5y agoSince you sound sincere here ... I read your comment as disagreeing with and correcting the original comment.
- smcl 5y agoOops, it wasn't intended! I think maybe the "but" in my comment makes it sound that way?
- Cederfjard 5y agoYeah, to me it reads ”that’s a nice theory you have, but now I’ll tell you mine, which I think is the correct one”.
- smcl 5y agoI just liked how they related the speed of sound to the distance between ears to explain the (possibly less than) ~0.5ms thing, and how it was nicer than the naive explanation I had previously assumed
- ryandvm 5y agoYou also wouldn't be able to do the cocktail party trick. Your brain's ability to ignore everything that isn't of the desired ITD phase shift is what allows you to selectively ignore most of the noise in the room and focus on a single conversation.
- mattkrause 5y agoIt's a combination of both. The relevant keywords are "Interaural Time Difference" (ITD; this phenomenon) and "Interaural Intensity (or Level) Difference" (IID/ILD; i.e., volume). In fact, there are a few other mechanisms too. The shape of the pinna (external ear) does some filtering that allows you to distinguish sounds that produce identical ITD/IID. The neuroscience of this is really fascinating, and the circuits have been worked out pretty well.