dB SPL
Pronunciation: dee-bee es-pee-el
Also written as: dB SPL — Decibels Sound Pressure Level
Decibels sound pressure level; an absolute physical measure of sound pressure referenced to 20 micropascals (20 μPa), the threshold of human hearing in a free field.
Full Definition
dB SPL (decibels sound pressure level) is an absolute measure of acoustic pressure expressed relative to a reference of 20 μPa, which approximates the average threshold of human hearing. Unlike dB HL, which is a clinical audiometric scale referenced to average normal hearing thresholds, dB SPL is a physical measurement used in acoustics, real-ear measurement, and hearing aid specification. Editors must maintain the distinction between dB SPL and dB HL, as conflating them introduces significant clinical and technical errors. The abbreviation is always formatted as 'dB SPL' (uppercase SPL, no hyphen) in accordance with standard audiological convention.
Usage
Usage note: Do not hyphenate. Always distinguish from dB HL in clinical documents. 'SPL' is always uppercase.
In Context
- "The real-ear aided response was measured in dB SPL at the tympanic membrane using a probe microphone." — Hearing aid verification report
- "The author has used dB SPL and dB HL interchangeably in Table 2; this must be corrected before publication." — Copy-editing query