Objective: Congenital aural atresia causes severe conductive hearing loss disturbing auditory development. The differences in speech recognition were investigated between bilateral and unilateral aural atresia.
Design: The maximum speech recognition scores (SRSs) were compared between patients with bilateral and unilateral aural atresia. In patients with unilateral aural atresia, the maximum SRSs were compared between the atretic and unaffected ears. Furthermore, the correct response rates for test material monosyllables were compared with those of patients with sensorineural hearing loss (SNHL), which had been previously obtained.
Study sample: Twenty-four patients with aural atresia (8 bilateral, and 16 unilateral) participated.
Results: The maximum SRS in unilateral atretic ears (median: 72%) was significantly lower than that in unaffected ears (median: 89%) (p < 0.05) and in bilateral atretic ears (median: 91%) (p < 0.05). Patients with aural atresia had relatively high correct response rates for monosyllables with low correct response rates by patients with SNHL. Conversely, incorrect responses were obtained for several words for which high correct-response rates were attained by patients with SNHL.
Conclusions: Poor unilateral atretic-ear development may induce low speech recognition, and the mechanisms underlying speech-recognition reduction differ from those in SNHL.
Keywords: Aural atresia; auditory development; conductive hearing loss; speech perception; unilateral hearing loss.