Audiometric Zero
The standardized reference sound pressure level calibrated to represent the average threshold of hearing in young, otologically normal adults at each test frequency, forming the 0 dB HL baseline.
Full Definition
Audiometric zero defines the 0 dB Hearing Level (HL) reference for each audiometric test frequency and is derived from international standards (ISO 8253-1 and ANSI S3.6). It does not represent the physical absence of sound but rather the statistically derived minimum audibility threshold across a normative population. Editors reviewing audiology methodology sections must understand that dB HL values are only meaningful relative to this reference; absolute sound pressure level (dB SPL) values are not clinically interchangeable with dB HL values. The term 'audiometric zero' is distinct from 'zero dB HL'—the former refers to the reference standard, the latter to a single point on the audiometric scale.
Usage
Usage note: Do not equate with physical silence or absolute zero sound energy. Ensure calibration standards cited (ISO vs. ANSI) are applied consistently within a document.
In Context
- "The audiometer was calibrated to audiometric zero according to ISO 8253-1 before the evaluation commenced." — Audiological evaluation report — methods section
- "Authors who conflate audiometric zero with dB SPL should be queried, as the values differ by frequency-dependent offsets." — Research manuscript editorial guidance