Purpose: Cartilage conduction hearing aids (CC-HAs) are novel hearing aids using the third hearing pathway of cartilage conduction. We assessed the efficacy of CC-HAs in adult hearing-loss patients who had various anatomical conditions of their ear canal(s) and determined who are good candidates for CC-HAs.
Methods: Patients (n = 37) were categorised into three groups of participants based on ear canal anatomy: (1) canal stenosis; (2) abnormal canal; (3) normal canal. After a 1-month free trial of normal usage, CC-HA-aided and unaided hearing thresholds (43 fitted ears) were determined using standard audiograms, after which participants could choose to purchase the device or not. Group and subgroup purchase rates were calculated along with the purchase reason (or not). Subgroup binary analysis of purchase rates was done according to hearing loss severity (< 70 dB and ≥ 70 dB) of unaided average air conduction (AC) hearing thresholds.
Results: CC-HA provided hearing improvements in all frequencies within each group. Overall, 60.47% of participants purchased a CC-HA after the trial. Over 70% participants with canal stenosis purchased CC-HAs, regardless of their AC hearing thresholds (severe vs. mild), and significantly more mild-loss participants in the abnormal canal group purchased their trial CC-HA compared to severe-loss participants (85.71% vs. 20%).
Conclusion: Adult patients with ear canal stenosis or closure are the best candidates for CC-HAs, regardless of their hearing thresholds. Patients with more severe hearing loss accompanied by ear canal anomalies and patients with normal canal anatomy may not be good candidates.
Keywords: Adult; Cartilage; Ear canal; Hearing aids; Hearing tests; Stenosis.