1. Why does a warm horn play sharper than a cold horn? Sound travels faster in warm air than in cold air. This means that a sound wave gets from one end of a piece of tubing faster if the air is warmer. In turn this means that the resonant frequency of a particular length of tubing is higher when the air inside is warmer.
2. Would different alloys effect how much the pitch changes with temperature? Not to any significant degree. In principle, different alloys expand by different amounts with changes in temperature, thus increasing the length of the resonant tube and so reducing its resonant frequency. This counteracts the effect of sound travelling fater in the air inside. But within the ordinary range of room temperatures, the amount by which metal expands with increasing temperature is insignificant compared to the increase in the speed of sound in air over the same temperature range. So the effect of the air is the dominant effect. 3. And finally, does a tuning fork go a little sharp when it's warmed? No. If anything it would go *very* slightly flat. But you would probably need some pretty good measuring equipment to detect the change over a temperature range within normal "room temperature" limits. The unassisted human ear isn't going to notice any diffierence at all. Regards Jonathan West _______________________________________________ post: [email protected] unsubscribe or set options at https://pegasus.memphis.edu/cgi-bin/mailman/options/horn/archive%40jab.org
