The speech perception gap in cochlear implant patients

To determine how commonly word recognition scores obtained using insert microphones (PB max) overestimate word recognition scores obtained through appropriately fit hearing aids (A-WRS).

Aided speech recognition tests may not be performed during routine hearing aid fittings; however, they are regularly performed for cochlear implant (CI) candidacy evaluation. Therefore, audiologic data from CI recipients were queried in a retrospective cohort study at a tertiary care center. PB max and A-WRS were obtained. The Speech Perception (SP) gap, defined as PB max minus A-WRS, was calculated for each patient and a high SP gap was defined as ≥20%.

Analyzing 78 patients with complete data, 30 patients had PB max ≥20%. Of these, 18 (60%) had a high SP gap. Eighteen of the 78 patients had PB max ≥40%, and of these patients, 15 (83%) had a high SP gap.

A Speech Perception Gap of ≥20% may exist in a sizable percentage of patients with hearing loss. Our pilot study suggests that over 80% of these patients could have Class D hearing (speech recognition <50%) using conventional hearing aids and may be better served using alternate rehabilitation strategies such as middle ear or cochlear implants. Therefore, aided speech testing should be performed as part of a verified hearing aid fit in all patients, especially those with PB Max ranging from 40% to 70%.