Thanks, Curt. Your central argument -- that the number of oscillations per second is unaltered by the medium through which the sound travels -- is entirely the correct one.
Curt Austin <[email protected]> wrote: William: But saying the wavelength changes is not the same as saying the frequency changes. The wavelength changes as the medium changes so as to keep the frequency constant. The formula you are referencing gives the relationship between the two. Think of it this way: if 100 oscillations enter into a medium in one second, they will all exit the medium in one second. If fewer oscillations exited, and the sound was continuous, you'd have oscillations accumulating inside - eventually, there would be a loud bang. If more exited in one second, yikes, that might be even worse. But the following has nothing whatever to do with anything. It is not necessary to introduce dolphins into the argument. If I take a full lung on helium and sing, the helium will greatly raise the pitch eitted by my vocal machinery. But whether the medium between me and the listener is helium, air, water, or cream cheese has no additional effect on the frequency. It may have effect on how long I can keep going before death intervenes. Hans apparently both agrees and disagrees: But how should this affect the intonation ? 440 remains 440, no matter what kind of curtain or deco they use on stage. But the distance effects (lowers) the intonation of a given pitch. We all learned that in school (classic gymnasium, physics classes) which seem to be abandoned in a greater percentage of schools. This claim about "distant effects" is nothing more than argument by authority. The schools in Hans' country (like schools pretty much everywhere) have from time to time taught things that are patently false. I would expect Hans, if he was actually taught this, to be able to explain the mechanisms of physics by which it is true, and not just parrot back that too many of us are uneducated. I shall await Hans to explain the physics. While we wait, let's try to move the discussion along: There have been two not-quite-equivalent terms used on this thread. Under usual interpretation, "frequency" is simply vibrations per second, but "pitch" is the tone-height perceived by a human. These are mostly the same for continuous sounds (although there are subtle effects of volume) but are often very different for percussive ("decaying") tibres. Percussion instruments such as the piano, especially in the low range, are quite inharmonic. A human (including those humans who are piano tuners) perceive a very different pitch than the frequency of the lowest pseudo-harmonic of the vibrating piano string. This is not of immediate interest in our discussion of distant, offstage instruments, which are generally playing essentially continuous harmonic tones. Hans' suggested sharpening of the main tuning slide by 1/4 inch would correspond to a sharpening of about 6 cents (on F horn). I don't discount that there might be some other _perceptual_ effect of distance that would cause this sharpening to feel correct from the stage. But if Hans remembers what he was taught in Gymnasium Physics, he ought be able to explain the effect. Here's an experiment that would illuminate, if anyone (especially Hans or Bob, both of whose intonation we can trust and who believe in this offstage effect) were in position to execute it. Place a player offstage, adjusting the intonation as he believes necessary. Place another player on stage, siilar instrument, playing at normal pitch. Have these two performers alternatively play the same note, such that the on stage player and an independent observer feel that they are compatible. Then have them play these same notes together. Will there be beats? If there is some reason that we perceive a note played at distance lower than its frequency, there will be beats. If this offstage-sounds-flat theory is simply incorrect, there will be no beats. _______________________________________________ post: [email protected] unsubscribe or set options at https://pegasus.memphis.edu/cgi-bin/mailman/options/horn/archive%40jab.org
