Abstract:

A virtual sound level meter has been designed using the LabVIEW[sup (registered)] programming language for use in a CD/ROM-based distance education course, developed and taught by instructors from the Penn State Graduate Program in Acoustics. The purpose of the virtual instrument is to reinforce concepts presented in the lectures by providing students hands-on experience in applying the principles. The meter was designed using ANSI standard S1.4, Specification for Sound Level Meters. All of the functionality prescribed by standard S1.4 is incorporated in the virtual sound level meter. As a signal input the user can specify the frequency and magnitude of a number of deterministic signals, such as a sine wave. Uniform or Gaussian random noise of a user selected magnitude can then be added to the deterministic signal. The student can apply various weightings, third-octave filters, and integration times to the signals. The raw time series, filtered time series, and calculated SPL are displayed on the front panel of the virtual instrument allowing the student to visualize the original signal and the results of the signal conditioning.