Digital-to-analog conversion of acoustic signals
M. Scott Morgan, Lee N. Bolen · The Journal of the Acoustical Society of America · 1990
This paper describes the theory, construction, and operation of a transducer that is capable of transmitting an analog acoustic signal when driven by a digital input signal. The digital signal drives a capacitive dielectric transducer whose active surface area is proportional to the magnitude of the digital signal. The output of the transducer contains the original analog signal in addition to higher frequency Fourier components that result from the sampling process. The unwanted additional signal is attenuated when the transducer output is fed into an acoustic low-pass filter whose response is determined by using electrical circuit analysis techniques. Results indicate that this system is useful for signals that have an upper frequency limit that does not exceed 8 kHz.