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Figure 3a

Figure 3a: Waveform display of the native version of the 11.025 kHz / 16-bit multiple
sine wave signal over 15.0 milliseconds.

Waveform display of the native version of the 11.025 kHz / 16-bit multiple sine wave signal over 15.0 milliseconds. Time is on the horizontal axis moving from left to right, and amplitude is on the vertical axis. The signal comprises four sine waves having frequencies of 500, 1400, 2600, and 3400 hertz, which have been combined to produce a compound signal. The positive and negative peaks have amplitudes that are 1 decibel below their maximum possible values.