I've been trying email clients, and had a cockpit error. I wanted to make a couple comments.
First to Alan, N5ILN, I do have a copy of Schrader's 'Electronic Communications". I agree. Then, this story: I began using my laptop at my daughter's house. Pretty soon, people from all over the house, even from downstairs, converged on me asking why the laptop was making such a terrible screeching noise. They couldn't tolerate it. I wasn't hearing a thing. I hit the mute button and they were happy again. No hearing aids yet. I wonder if that affects my preference for CW sidetone around 600 Hz. I think that is normal?? Dick, n0ce ----- Original Message ----- From: Jim Brown To: [email protected] Sent: Wednesday, August 07, 2013 4:23 AM Subject: Re: [Elecraft] [K3] Hearing aids, meet K3 On 8/6/2013 8:45 PM, Don Wilhelm wrote: > I may b unique because my lower range hearing without the aids is > normal, so I have built-in low pass filters in my ears. That's entirely normal, Don. In general, hearing loss starts at the high end and moves down. Many folks with a lot of hearing loss still hear a lot of low end. The exception is when for one reason or another we are exposed to strong noise at a specific frequencies, or a specific range of frequencies, in which case we develop a notch in that range. The problem is that speech intelligibility depends on sounds in the range of 500 Hz - 4 kHz, with the 2 kHz octave being most important, the 1 kHz octave close behind. That's why telephones and ham radio, with bandwidth limited to about 500 Hz to 3kHz, work just fine. Energy above 4 kHz helps, but energy below about 350 Hz makes no contribution, and often makes things worse. The scientists at Bell Labs figured this stuff out early in the 20th century. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
