The speech perception gap in cochlear implant patients

Objective: 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). Methods: 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%. Results: 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. Discussion/conclusion: 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%.