snoopy@ecrcvax.UUCP (Sebastian Schmitz) (07/05/85)
Summary: Expires: References: <unc.532> Sender: Reply-To: snoopy@ecrcvax.UUCP (Sebastian Schmitz) Followup-To: Distribution: Organization: European Computer-Industry Research Centre, Munchen, W. Germany Keywords: I have found that this varies from monitor to monitor i.e. just keep swapping till you find one that does not whine. It is annoying though. "Normal" TV's do the same: I can usually walk out on the street underneath peoples windows and tell you who has his TV turned on or not just by hearing the whine (and not the soundtrack). Well I may have bats ears but it is annoying. Incidentally the whine you hear is the flyback transformer which means you either hear the very annoying aprox. 18.5 KHz tone or subharmonics thereof (which are less annoying but usually louder). I remember that some years ago there was plenty of discussion on net.works if one should not pressurise manufacturers to do something against this whine. This would be another big point on the "our monitors have such lovely ergonomics list". There would be a BIG market, I think... So anyone building monitors please take note of this. I think that headaches people get using CRT's are not due to eye strain but rather due to the sound... /* this is true probably because high pitched sound can cause intense pain in the inner ear. This principle is used by a US Army "sentinel robot", which prowls by the side of military fences, looks at you with its infrared sensors and orders you to stop whatever you are doing or else. The "or else" means it will flash at you with a megawatty flash gun (to blind you, duuhhh) and if you run/stumble away it will come after you at up to 30 m.p.h. and will irradiate the surroundings with "a high frequency sound source which causes intense pain in the inner ear." In other words if you have not been scared shitless up to now, nows the time ! The article further claimed that so far there "were no plans to equip the robots with any lethal restraints". I don't know where this was published but it was some year or so ago on the last page of some electronic news magazine (could have been BYTE even). This last page was a sort of "last minute news" section. However I believe my quotes to be accurate and if anyone remebers the magazine please mail me the reference */ Perhaps someone can investigate this more formally (i.e. put a bunch of summer students in a terminal room, let them bash out memos of highly naive/political content to inapropriate newsgroups and bombard them with high frequency sound and plot typing error frequency against noise pitch/intensity. ;-) ) Happy whining and dining :-) /* groan - someone get me off the net !*/ love, -- Love, Sebastian (Snoopy) "You haven't done it, till you've done it with pointers" \!mcvax\!unido\!ecrcvax\!snoopy /* N.B. valid csh address */
lauren@vortex.UUCP (Lauren Weinstein) (07/06/85)
Actually, here in the U.S. the flyback is even more likely to be heard since it's about 3 Khz lower. I've heard stories of people quieting down noisy flybacks by coating them with caulking--but I have no idea if this works or if it might have undesirable safety or other side-effects. As monitors age previously quiet units sometimes start the whine. They drive me crazy, too. I also hear ultrasonic motion detectors (the sound sources for which are often left on all day while only the alarm is switched on and off) and some dog whistles (you don't really "hear" the latter, but you "feel" it in a very uncomfortable fashion. Makes me wonder what it sounds like to a creature more attuned to that frequency range.) One cure, as noted earlier, is lots of very loud rock music over a period of time, or lots of plane flights, ideally near the engines when possible. Simple human aging also, supposedly, reduces high-frequency response just in the normal course of things. --Lauren--