Technique for Objective Speech-Level Measurement
Peter D. Bricker · The Journal of the Acoustical Society of America · 1965
The technique described here provides a measure of speech level that is free of the subjectivity inherent in meter reading. A speech-envelope detector remains operated during intervals over which measurement is to be made (“speech spurts”) and gates two counters. One of these accumulates speech-spurt durations and the other accumulates a measure of the energy in each spurt. The ratio of the latter reading to the former, after any desired number of spurts, is the average absolute voltage over speech spurts. This technique is similar in form to the procedure used by a VU-meter reader, but is entirely objective. The resulting measure has a simple physical meaning and is highly reliable. Data presented include the relation to VU readings, performance in predicting loudness matches and loudness estimates, and comparisons of absolute voltage with other measures of the waveform taken by the same procedure.