6.77 transducer voltage coupling loss; coupling loss. Of an electroacoustic transducer consisting of a sound-receiving element (e.g., microphone or hydrophone) and associated electrical system, for a specified frequency, ten times the logarithm to the base ten of the ratio of the time-mean-square of the open-circuit output voltage of the electroacoustic element to the time-mean-square of the open-circuit voltage of the associated electrical system. Unit, decibel (dB).
Annotation To facilitate the use of an electroacoustic element having a high electrical impedance, the element is usually combined with a device such as a preamplifier or transformer. A piezoelectric hydrophone, for example, may consist of a crystal and preamplifier. The free-field voltage sensitivity is then specified in terms of the open-circuit crystal voltage.« Back to Standards Terminolgy Index