Cochlear implant surgery was performed on 13 patients with postmeningitic deafness (seven adults, six children). Two adults and two children (30.8%) had severe labyrinthitis ossificans requiring radical "drill-out." Five of 13 (38.5%) had some bone growth requiring partial drill-out, and four of 13 (30.8%) had normal insertion with no drill-out. Hearing results for patients with no bone growth were similar to nonmeningitic patients; three of four (75%) had open-set speech recognition. Performance of patients with total drill-out was poor; "auditory only" performance was limited to detection and pattern perception of speech, and no patients had open-set speech recognition. Results for patients with partial drill-out were similar to results in patients with no bone growth. Labyrinthitis ossificans not only presents surgical challenges to cochlear implantation but may also adversely affect hearing outcome.

This study investigated the relationship between acoustic damping of hearing aid responses and listeners’ speech discrimination and judgments of preference and sound quality. Eighteen subjects with essentially equivalent hearing impairments participated. Subjects’ speech discrimination was evaluated for a male talker in quiet and in noise and for a female talker in the same conditions with hearing aids with 0 dB, −5 dB, and −10 dB of damping. Subjects also compared the damping levels using eight bipolar adjective pairs and provided judgments of overall preference. Measurements of the hearing aid responses were made in a 2-cm 3 coupler and in the subjects’ ears using probe microphone techniques. Smoothness of the responses was quantified using the Index of Response Irregularity (IRI) and the Frequency Response Smoothness Quantification Index (FReSQI). Subjects preferred the two damped hearing aid responses to the undamped. They also had better speech discrimination with damped hearing aid responses. The bipolar adjectives were of limited use in comparing hearing aids. A few questions about hearing aid sound quality and preference appear adequate for evaluating listeners’ choice of hearing aids. Smoothness of the hearing aid responses in the test box was higher for the damped hearing aids than for the undamped. However, for real ear responses measured using a probe microphone, smoothness did not change as a function of damping level.

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