Pressure transducer for musical instruments

DETAILED DESCRIPTION According to the present invention, a pressure transducer is employed as a pressure sensor in musical instruments having an air column through which pressure variations pass in producing sounds, such as in wind instruments and drums.
A noiseless voltage preamplifier couples the transducer to a power preamplifier the output of which may then be amplified in a conventional audio amplifier.
In the case of a wind instrument, the transducer is mounted between the cup or reed of the mouthpiece, and the first key or finger hole, or in the air column in a direction opposite the first key or finger hole in the case of a transverse flute or similar reedless woodwind instrument for direct communication with the air column of the instrument.
The transducer is preferably comprised of four piezoresistors arranged in a Wheatstone bridge arrangement on a semiconductor chip etched on the back to form a diaphragm.
The etched back is bonded to a substrate to form a sealed cavity on one side of the diaphragm.
Such a transducer in the air column of a musical instrument provides omnidirectional pick up with excellent fidelity in that it will not only have all of the frequencies of the sound but also their amplitude (the envelope).
The novel features that are considered characteristic of this invention are set forth with particularity in the appended claims.
The invention will best be understood from the following description when read in connection with the accompanying drawings.