Lobdell Bryce E, Allen Jont B
Beckman Institute, University of Illinois, Urbana, Illinois 61801, USA.
J Acoust Soc Am. 2007 Jan;121(1):279-85. doi: 10.1121/1.2387130.
The Volume- Unit (VU) meter, used in speech research prior to the advent of computers and modern signal processing methods, is described in signal processing terms. There are no known software implementations of this meter, which meet the 1954 ASA standard and provide the instantaneous needle level. Important speech applications will be explored, such as making comparisons of speech levels to earlier classic works, and measuring speech levels using traditional methods on modern computers. It is our intention to make this venerable method of measuring speech levels available once again. The VU meter is simulated and its properties are studied. A 1950s vintage and a recent vintage VU meter are studied by comparing the transient responses to tones and measurement of speech levels. Based on these measurements, a software VU meter (henceforth referred to as VUSOFT) is simulated, and verified. The method for reading the meter is explained, and simulated in software. The VU level for speech is shown to depend on the reading duration. The relationship between the root-mean-squared (rms) level of a signal and the VU level of a signal is determined, as a function of the meter-reading time.
在计算机和现代信号处理方法出现之前，语音研究中使用的音量单位（VU）计，将从信号处理的角度进行描述。目前还没有已知的符合1954年美国声学学会（ASA）标准并能提供瞬时指针电平的该种仪表的软件实现。将探讨重要的语音应用，例如将语音电平与早期经典著作进行比较，以及在现代计算机上使用传统方法测量语音电平。我们的意图是让这种古老的测量语音电平的方法再次可用。对VU计进行了模拟并研究了其特性。通过比较对音调的瞬态响应和语音电平测量，研究了一台20世纪50年代的老式VU计和一台最近的老式VU计。基于这些测量，模拟并验证了一种软件VU计（以下简称VUSOFT）。解释了读取仪表的方法并在软件中进行了模拟。结果表明，语音的VU电平取决于读取持续时间。确定了信号的均方根（rms）电平与信号的VU电平之间的关系，该关系是仪表读取时间的函数。
