Insertion Gain
Also written as: REIG — Real-Ear Insertion Gain
The decibel difference between the sound pressure level in the ear canal with a hearing aid in place and the sound pressure level without it, measured at the eardrum.
Full Definition
Insertion gain is an electroacoustic metric obtained during real-ear measurement, representing the actual amplification delivered by a hearing aid at the eardrum. It is calculated as the real-ear aided response (REAR) minus the real-ear unaided response (REUR). Insertion gain accounts for the individual ear-canal acoustics of each patient, making it a more precise verification measure than coupler gain. Editors should distinguish insertion gain from functional gain (a behavioral measure) and from coupler gain (a standardized cavity measurement that does not reflect individual ear-canal characteristics).
Usage
Usage note: In formal reports, insertion gain should be specified alongside the prescriptive target against which it is being compared (e.g., NAL-NL2, DSL v5).
In Context
- "Insertion gain at 3000 Hz was 35 dB, meeting the prescribed NAL-NL2 target." — Hearing aid verification clinical note
- "The audiologist documented insertion gain curves across the speech frequency range." — Real-ear measurement report