Page 58 - Master Handbook of Acoustics

difference in readings shows that the signal has significant low-frequency content. A weighting is also
described in the IEC 61672 standard.
Simple frequency weightings such as these cannot accurately represent loudness. Measurements

made with simple weightings are not accepted as measurement loudness levels, but are only used for
comparison of levels. Frequency analysis of sounds is recommended, using octave or 1/3-octave
bands.

Sine-Wave Measurements

The sine wave (or sinusoid) is a specific kind of alternating signal and is described by its own set of
specific terms. Viewed on an oscilloscope, the easiest value to read is the peak-to-peak value (of
voltage, current, sound pressure, or whatever the sine wave represents), as shown in Fig. 2-4. If the
wave is symmetrical, the peak-to-peak value is twice the peak value.