In message <200601220606_mc3-1-b660-e...@compuserve.com>, dated Sun, 22 Jan 2006, Cortland Richmond <72146....@compuserve.com> writes
>>> The reason is that there are MANY ways to damage your hearing and >playing a CD player too loud is just one. Also, we don't have any >evidence that a significant number of people DO play them too loud. The ><< > >Leaving aside whether there is indeed a need for such a limit... There is significant evidence that some young people are damaging their hearing. But this is much more likely to be due to clubbing than to portable audio products. Orchestral players wear ear-plugs these days. > >It seems to me that the only way to reliably limit the sound pressure >applied to eardrums is to require a physical limit on the amount of air >an *earphone* can move. Without knowing the acoustic efficiency of >whatever transducer a user has, it is difficult, and perhaps >impossible, to do so at the electronics end. Yes, that's what EN 55032-2 simply doesn't work, since that is what it tries to do. EN 55032-1 applies to players sold with their headphones, limits the sound pressure level from the headphones when fed from the player, and the test conditions are with everything 'set to maximum'. This isn't realistic even for heavy-metal material, and pretty disastrous for classical music. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk 2006 is YMMVI- Your mileage may vary immoderately. John Woodgate - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
