A New Standard Volume Indicator and Reference Level

Comparison of vu-meter-based and rms-based calibration of speech levels

“…In 1940, Chinn et al 1940 published the paper describing the vu meter. The vu meter was fairly soon adopted for speech research and audiology, and has been the basis for the standard method for setting the calibration tone on a speech recording, which is that "…the rms sound pressure level of a 1000 Hz signal [is] adjusted so that the vu meter deflection produced by the 1000 Hz signal is equal to the average peak vu meter deflection produced by the speech signal."…”

Audiometric Calibration: Speech Signals

“…This presented difficulties in measuring speech levels conveniently and reliably prior to the introduction of digital technology. The volume-unit (VU) meter was an analog instrument developed for the specific purpose of measuring speech levels 16 The ballistics of the meter were designed to track major temporal fluctuations of speech at a rate that can be followed by the human eye. It was a useful instrument, but it had limitations in that there were large between-operator differences in reading the meter.…”

Amplitude (vu and rms) and Temporal (msec) Measures of Two Northwestern University Auditory Test No. 6 Recordings

“…ntil digital technology became commonplace, the only standardized instrument readily available to monitor the amplitude or relative level of speech signals was an analog volume-unit (vu) meter 1 that was developed as a collaborative effort by the Columbia Broadcasting System, the National Broadcasting Company, and the Bell Telephone Laboratories (Chinn et al, 1940). Before 1940, signal amplitudes could be quantified in terms of average, root mean square (rms), and peak voltages, but there was a need by the radio broadcasting companies to express the amplitude of speech signals in a "simple numerical fashion."…”

“…Before 1940, signal amplitudes could be quantified in terms of average, root mean square (rms), and peak voltages, but there was a need by the radio broadcasting companies to express the amplitude of speech signals in a "simple numerical fashion." To meet this need, the vu meter was conceived (note : Chinn et al, 1940 andChinn, 1951 provided detailed accounts of the development and characteristics of the vu meter). The vu meter, an example faceplate of which is shown in Figure 1, continues in common and practical usage in the broadcast and recording industries, but has been replaced on many instruments, including audiometers, by digital bar meters whose characteristics are seldom specified.…”

“…The vu meter, an example faceplate of which is shown in Figure 1, continues in common and practical usage in the broadcast and recording industries, but has been replaced on many instruments, including audiometers, by digital bar meters whose characteristics are seldom specified. Chinn et al (1940) described the detail considerations that were incorporated into the vu meter. For example, even the faceplate design received considerable attention that ranged from the length and arc of the scale, the off-vertical location of the scale reference (zero) at 71% of full scale, the scale 220 to 13 for vu divisions with the 220 to 0 divisions in black and the 0 through 13 divisions in red, the shape of the pointer or needle, and the faceplate background color (cream yellow).…”