Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!clyde!rutgers!cmcl2!brl-adm!husc6!think!ames!sdcsvax!telesoft!dar From: dar@telesoft.UUCP Newsgroups: comp.sys.amiga,comp.sys.mac,comp.sys.atari.st,rec.music.makers,rec.music.synth Subject: Re: Sonic Holography. (ever increasing tone) Message-ID: <130@telesoft.UUCP> Date: Fri, 4-Dec-87 16:45:44 EST Article-I.D.: telesoft.130 Posted: Fri Dec 4 16:45:44 1987 Date-Received: Wed, 9-Dec-87 20:56:06 EST References: <7536@eddie.MIT.EDU> <2476@gryphon.CTS.COM> Organization: TeleSoft Inc., San Diego, CA Lines: 17 Xref: utgpu comp.sys.amiga:11107 comp.sys.mac:9428 comp.sys.atari.st:6191 rec.music.makers:1031 rec.music.synth:1857 Summary: ever increasing (Sheppard's) tone The classic tone which constantly rises in pitch is called a Sheppard's tone (spelling?). It is very well know in psycho-acoustic circles. It is fairly easy to compute the samples for on a computer (e.g. something running CMusic), but would probably be tricky on a MIDI synth - largely a matter of blending amplitudes/spectra correctly. Diana Deutch, of the Univ. of Calif. San Diego, played Sheppard's tones and other interesting audible illusions at an Audio Engineering Society (AES) convention in Los Angeles (perhaps '82?). Also, Roderer's "The Physics and Psycoacoustics of Musical Sound" (or something like that - the bibliography part of my brain is off-line at the moment) probably discusses it in detail. Any good university library should have MANY references. -David sdcsva!telesoft!dar, dar@sdcsvax.(uucp,arpa,com,edu)