Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!wivax!decvax!yale-com!leichter From: leichter@yale-com.UUCP Newsgroups: net.audio Subject: Re: hearing.high.treble Message-ID: <1701@yale-com.UUCP> Date: Sat, 2-Jul-83 09:24:53 EDT Article-I.D.: yale-com.1701 Posted: Sat Jul 2 09:24:53 1983 Date-Received: Sun, 3-Jul-83 01:06:57 EDT References: whuxk.227 Lines: 27 Most of what you say about hearing the high end is true, but I have to dis- agree with one statement: Separation above 16KHz is important because the sound there is so directional. While it is true that the SOUND is highly directional, what matters is whether your HEARING is directional; and, in fact, it isn't. Human direction location is best in the midrange. It fades out in effectiveness at both ends, even under ideal circumstances. (There are several different mechanisms that the brain uses simultaneously, inclu- ding at least phase differences, gross timing differences, and the shadowing effect of the head. At very high frequencies - certainly at 16KHz - the only one left that works is the shadowing system; in the mid-range, several contribute and overall system performance is much better.) In addition, "ideal circumstances" are unlikely. 16KHz tones will bounce off everything in your listening room very effectively, and further you'll get standing waves all over. Turning your head slightly, or moving it a small amount, can produce large changes in volume. The directional information just isn't there to be found easily, even by a better system. (I can remember trying to find the bad power supply in a room full of systems when its Sonalert went off (a more or less pure tone up around 16KHz or so). You could hear the damn thing loudly everywhere in the room - but even standing in front of the bad unit, you couldn't tell that it was the source. The only way we were sure we had found the right one was the feeling of relief at the silence when we turned it off.) Anyway...While separation at 16KHz wouldn't be a negative, I doubt you would hear the difference between, say, 12db and 20db. -- Jerry decvax!yale-comix!leichter leichter@yale