Early Development of Measurement Microphones, the Audiometer and its use in Sound Evaluation, the Decibel, and the Sound Level Meter

In the late 1800s and early 1900s, much effort went into devising an accurate and portable means of measuring sound. Along the way, one of these efforts resulted in the accidental invention of the audiometer which was later then used for comparative listening evaluation of sound before sound level meters became available. This paper will concentrate on measurement microphones, the audiometer, the decibel, and the sound level meter.