Wait a minute, this cannot be right: (From a forum I found discussing this subject:) The speed of a wave (c) is given by multiplying the wavelength and thefrequency together (c = l * f) and this can be re-arranged to find thefrequency of the sound wave (in other words how high it sounds) (f),thus : "frequency = speed divided by wavelength" or f=c/l.
If you have the same wavelength, and the speed changes, then the frequency changes. This stands to reason because moving a speaker towards/away from you changes the relative speed, and thus the frequency changes. What is frequency but the number of times something happens, right? So, with a different speed, the rate of frequency MUST change. Correct me if I'm wrong, please, but according to this basic function speed of sound DOES effect pitch. As for your examples, at least one is completely wrong: 1) A telephone is not transmitting sound directly. It is converting it to an electronic signal, which then gets sent at the speed of light. 2) Sounds underwater have to be corrected and changed in terms of frequency to know what they would sound like in air 3) As for the fridge, it all depends on if both the speaker and mic are in the same fridge, or if one is outside of a colder body of air and the other is not. I'd have to run the experiment myself, but it seems from the math this would have some effect although it would be difficult to measure. Also, you say that only the temperature in the instrument effects frequency, but if the speed of sound itself DOES change with air temperature (and this is a fact), then the frequency MUST change if the wavelength is the same. -William -----Original Message----- From: Steve Haflich <[email protected]> To: The Horn List <[email protected]> Sent: Sun, May 29, 2011 6:24 pm Subject: Re: [Hornlist] offstage brass [email protected] wrote: What the sound has to travel through before getting to the audience has a great deal to do with pitch. You need to think a little more about the above statement. It is incorrect. Air travels at different speeds through different mediums, so thick walls and thick stage matter could have a slight effect on when the sound arrives to the audience, and how. The speed at which the sound travels has absolutely no effect on pitch. You can listen inside a refrigerator. You can put on scuba gear and listen underwater. You can put the sound into a telephone and send it electronically at essentially the speed of light to loudspeaker on another continent. None of this will have and effect on the frequency when the sound reaches the listener. It will effect the _delay_ between source and receiver, but not the frequency of the sound. The temperature of the medium affects the pitch as well, so it's very well possible that the temperature off stage could be very different from on stage, due to hot lights, etc. Every time I can remember being under a stage or off stage, it was much colder than on stage. It is only the temperature of the air in the oscillating instrument that affects frequency. Once the sound is emitted from the instrument, the temperature of the medium through which it travels has no effect on frequency. _______________________________________________ post: [email protected] unsubscribe or set options at https://pegasus.memphis.edu/cgi-bin/mailman/options/horn/valkhorn%40aol.com _______________________________________________ post: [email protected] unsubscribe or set options at https://pegasus.memphis.edu/cgi-bin/mailman/options/horn/archive%40jab.org
