Temperature compensated piezoelectric buzzer

A piezoelectric buzzer, comprising:

• a) a diaphragm that can be vibrated by a piezoelectric material powered by an electric current to produce a buzzing sound;
• b) a housing substantially enclosing said diaphragm, wherein said housing defines a resonating chamber that includes at least one sound emission port that provides a passageway for sound waves emitted by the diaphragm to leave the resonating chamber, wherein said resonating chamber has an optimal resonating frequency fHt at a temperature T defined by:
• fHt=(vt/2π)(√(A/voL))
• where:
• vt is the velocity of sound waves in air at a temperature T,
• A is the effective area of the sound emission port,
• vo is the volume of the resonating chamber, and
• L is the effective length of the sound emission port;
• and
• c) a temperature compensating member that moves in response to a change in temperature across all or part of the temperature range 0° C. to 250° C. to change the value √(A/voL) at a rate and in a manner that at least somewhat balances the change in 1/vt across that same temperature range, thereby reducing changes in the product (vt/2π)(√(A/voL)) and consequently reducing any changes that would otherwise occur in fHt across that temperature range.