transmitting power response

6.58  sensitivity to electric power; transmitting power response. Of an electroacoustic transducer for sound emission, at a specified frequency, quotient of the time-mean-square sound pressure in a free field at a specified distance from the effective acoustic center of the transducer, and in a specified direction, by the electric power input. Unit, pascal squared per watt (Pa²/W).

Annotation              When the effective acoustic center of the transducer cannot be easily determined, the distance should be measured from the reference point of the transducer.