Participants and Eligibility Criteria
hearing loss
EAR DISEASE, BILATERAL HEARING LOSS, HEARING LOSS, MIDDLE EAR, PATHOLOGY
Participants 18 years and older who self-reported mild to moderate hearing loss in response to an advertisement and had no history of outer or middle ear disease 90 days before study inquiry were invited to attend a baseline session to establish candidacy based on comprehensive air- and bone-conduction audiometry. Participants with normal hearing thresholds (<20-dB hearing level [HL]) at all frequencies (0.5, 1.0, 2.0, and 4.0 kHz), who had possible outer or middle ear pathology, or who had severe hearing loss with thresholds at 0.5, 1.0, 2.0, and 4.0 kHz more than 80-dB HL at 2 or more frequencies were excluded. All participants had bilateral hearing loss. Furthermore, participants with air-bone gaps more than 20-dB HL at 3 or more frequencies between 0.5, 1.0, 2.0, and 4.0 kHz were excluded. As detailed in 