The measurement unit for digital clear sound in devices is referred to as a "sampling" or "sample," which captures the pitch and volume attributes of sound at specific moments. The standard sampling rate for CD-quality audio is 44,100 samples per second for stereo channels. Total Harmonic Distortion (THD) is also highlighted as a key measure of an audio device's linearity and clarity. While digital audio involves Analog-to-Digital and Digital-to-Analog conversions, the fundamental measures of sound clarity remain consistent with analog methods. This discussion emphasizes that the topic is rooted in audio engineering rather than physics.