3The audiological battery

FWhat the battery is for

The audiological battery answers two questions: how severe is the loss, and how much can the best hearing aids do about it?The first is the audiogram; the second — the decisive one — is measured by testing speech understanding with the patient's optimally fitted aids in place.

FTThe sequence of tests

A typical battery moves from unaided audiometry (pure-tone thresholds and word recognition) to aided audiometry (thresholds with the hearing aids on, confirming the access amplification provides), to the best-aided sentence test, and on to speech-in-noise. Each step narrows from “how much is audible” toward “how much is understood in real life.”

CThe decisive test

Candidacy turns on recorded sentence recognition in the best-aided condition. Standardised, validated materials such as the AzBio sentences make scores reproducible and comparable across visits and centres — essential when a number near a threshold decides whether a patient is offered surgery.[2012] Recording the speech, rather than using a live talker, removes lip-reading and speech-rate cues, so the score reflects hearing alone.

CThe best-aided condition

The word best-aidedmatters. The test must use the patient's optimally fittedhearing aids — verified, not assumed — because the whole point is to measure what amplification can achieve at its best before concluding it is not enough. A poorly fitted aid would understate the patient's potential and could send someone to surgery who did not need it. Done properly, the best-aided sentence score is the single most important number in the candidacy decision. The level at which it is presented — and the criterion it must fall below — is the subject of the next module.

TCVerifying the aids — and the standard battery

A best-aided score is worthless unless the aids are verified. Good practice goes beyond the audiogram: tympanometry, acoustic reflexes and otoacoustic emissions help characterise the loss, while the candidacy fit itself is checked by a biologic listening check, an electroacoustic check, and a real-ear probe-microphone measurement matched to a prescriptive target (NAL-NL2 or DSL) within about ±5 dB. If audibility is not verified, the right answer may be better hearing aids, not an implant — an optimal re-fit and home trial are an ethical pre-condition.

The materials are standardised too. The 2011 Minimum Speech Test Battery specifies CNC words plus AzBio sentences in quiet and noise (and BKB-SIN), all at 60 dBA from a single 0° loudspeaker in a calibrated booth — and HINT was retired from this role because it ceilings in many candidates, falsely disqualifying genuinely disabled aid users.[2008] For difficult-to-test patients, ASSR adds frequency-specific objective thresholds that distinguish severe from profound loss.