Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site birtch.UUCP Path: utzoo!watmath!clyde!cbosgd!ukma!psuvm.bitnet!psuvax1!burdvax!sdcrdcf!trwrb!scgvaxd!felix!birtch!oleg From: oleg@birtch.UUCP (Oleg Kiselev) Newsgroups: net.med,net.info-terms,net.audio Subject: Re: "Ultrasonic" hearing Message-ID: <251@birtch.UUCP> Date: Thu, 9-Jan-86 05:41:45 EST Article-I.D.: birtch.251 Posted: Thu Jan 9 05:41:45 1986 Date-Received: Tue, 14-Jan-86 03:23:56 EST References: <1280@brl-tgr.ARPA> <590@harvard.UUCP> <11370@ucbvax.BERKELEY.EDU> Reply-To: oleg@birtch.UUCP (Oleg Kiselev) Distribution: net Organization: The Real Estate Conspiracy Lines: 35 Xref: watmath net.med:3120 net.info-terms:794 net.audio:7108 In article <11370@ucbvax.BERKELEY.EDU> spp@ucbvax.BERKELEY.EDU (Stephen P Pope) writes: > > I've never encountered a TV receiver or monitor that >didn't emit an annoying high pitched squeal at at least a >low audible level. I don't know (or care) whether this is >15.75, 17 or 19 KHz ( the three numbers people usually >throw out). I suspect it is there because the receivers >are not built real well. A real solid frame and chassis would >almost certainly help. I have heard it is usually the vibration of transformers and/or capacitors (fly-back transformer?????). THe worst offenders I have heard were tvi925 . Sometimes a sharp rasp on the side of the terminal would silence it for an hour or so ( and many people got so irritated by the squeal they did it routinely). And what about the fan noise in large micros? > On a related subject, I understand that some native >tribes in quiet, undeveloped third-world areas have been >found to be able to hear well up to 40 or 50 KHz. Apparently, >the average westerner can hear only up to 12 to 20 Khz >mostly because of exposure to noise all his life. It was also said that their 60-70 year-olds had hearing in exess of that of the early 30's-late 20's eurpean urban dwellers ( the researchers). The oldsters also were very alert and had no hart illnesses.... Whoops! I have just realized MY terminal started squealing! jd,bc, d||{~| -- Disclamer: I don't work here anymore - so they are not responsible for me. +-------------------------------+ Don't bother, I'll find the door! | STAY ALERT! TRUST NO ONE! | Oleg Kiselev. | KEEP YOUR LASER HANDY! |...!{trwrb|scgvaxd}!felix!birtch!oleg --------------------------------+...!{ihnp4|randvax}!ucla-cs!uclapic!oac6!oleg