A pure tone’s peak amplitude is the maximum pressure it achieves per cycle.

Evidence

Due to the periodic (repeating) nature of a sinusoid and its simple characterization, a pure tone always reaches the same maximum and minimum amplitude each cycle. Consequently, the pure tone can be described with a single amplitude value. The a in Eq. 2–1 is the peak amplitude, the maximum amplitude value achieved by any sound wave. Figure 2–1 illustrates this stimulus with a peak amplitude of 1. Because sound is a pressure wave, the peak amplitude is a term often interchanged with the term peak pressure, or the maximum pressure achieved by the sound stimulus. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 174

Categorization

• DEFINE: Defines peak amplitude/peak pressure as the single amplitude value characterizing a pure tone.