Sound Pressure Level

A logarithmic measure of sound intensity expressed in decibels (dB), representing the pressure of a sound wave relative to a reference level. In accessibility, SPL is critical for designing auditory feedback systems—sounds must be loud enough to be detected above ambient noise but not so loud as to cause discomfort or hearing damage. Typical conversation occurs at 60-70 dB SPL, while assistive device audio cues often target 70-80 dB SPL to ensure audibility in various environments.