On Sun,3/1/2015 10:25 PM, Rick Tavan N6XI wrote:
Yes, I've noticed this. I have no real knowledge of why low tones seem to make for better copy in QRM but I have guessed that it has to do with the relative difference in interfering tone for a given offset from the desired signal. If you listen to 1000 Hz (which many ops do) and the interfering signal is 100 Hz away, the difference is only 10%. But if you listen to 400 Hz, the difference is 25%. So the filter in your brain may be more effective distinguishing 400 from 500 Hz than it is in distinguishing 1000 from 1100 Hz. Just a guess.
That's my audio professional's best guess too. In general, we humans hear logarithmically. Also, we hear differences in sounds that are separated by some "critical bandwidth" that is in the range of 1/3 to 1/6 of an octave. An octave is a 2:1 frequency ratio. So figure 2 to the 1/3 power and 2 to the 1/6 power.
I set my radios between 500 - 550 Hz. Those with severe high frequency hearing loss might want to try even lower frequency settings. Most (but definitely not all) hearing loss is greatest at the higher frequencies.
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 Message delivered to [email protected]
