Quote:
Originally posted by clapper
Are you sure that the curve should be included? It sounds as thou the program would, in essence, apply an EQ curve to the program (non-destructive to the file) before analysis, and thereby raise or lower the result?
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That is true, and that's essentially what Sound Forge would be doing. I would still recommend it be included because the objective is to make use of a quantifiable scale (dB of RMS power) that is as closely as possible related to the perceived volume level of the material. (Which should be as close as possible to the actual LAeq level of the material). Since the equal loudness contour applies a psychoacoustic model to the sound when computing the perceived loudness, you can view the application of this curve as an updated algorithm for computing the RMS power (if you're trying to associate RMS power with perceived loudness).
At any rate, if you don't believe the equal loudness contour should be used or is not applicable to the material, it can be turned off in Sound Forge's normalization dialog box.
Furthermore, I believe the difference in final measurement with and without equal loudness contour may be well within the tolerance/error that results from using an RMS power measurement rather than LAeq. I would state that if the error associated with using RMS is too high for your application, that you should probably be using a higher end tool to measure LAeq directly instead of RMS power.
I would like to actually test and see how close the various RMS measurements from Sound Forge and CoolEdit/Audition are getting to LAeq, but I unfortunately don't have any tool that can measure LAeq directly. Thus my "poor man's" approach to the entire problem.
