Effectiveness of a programable body-worn digital hearing aid for older adults in a developing country: a randomized controlled trial with a cross-over design

BACKGROUND: Hearing aids are important assistive devices for hearing rehabilitation. However, the cost of commonly available commercial hearing aids is often higher than the average monthly income of individuals in some developing countries. Therefore, there is a great need to locally produce cheaper, but still effective, hearing aids. The Thai-produced P02 hearing aid was designed to meet this requirement. OBJECTIVE: To compare the effectiveness of the P02 hearing aid with two common commercially available digital hearing aids (Clip-II™ and Concerto Basic®). METHODS: A prospective, randomized controlled trial with a cross-over design was conducted from October 2012 to September 2014 in a rural Thai community. There were 73 participants (mean age of 73.7 ± 7.3 years) included in this study with moderate to severe hearing loss who were assessed for hearing aid performance, including probe microphone real-ear measurement, functional gain, speech discrimination, and participant satisfaction with the overall quality of perceived sound and the design of the device. RESULTS: There were no statistically significant differences in functional gain or speech discrimination among the three hearing aids evaluated (p-value > 0.05). Real-ear measurements of the three hearing aids met the target curve in 93% of the participants. The best real-ear measurement of the hearing aid following the target curve was significantly lower than that of Clip-II™ and Concerto Basic® (p-value < 0.05) at high frequency. However, participants rated the overall quality of sound higher for the P02 hearing aid than that of Clip-II™ but lower than that of Concerto Basic® (p-value > 0.05). Participants revealed that the P02 hearing aid provided the highest satisfaction ratings for design and user-friendliness with statistical significance (p-value < 0.05). CONCLUSION: The P02 hearing aid was an effective device for older Thai adults with hearing disabilities. Additionally, its modern design, simplicity of use, and ease of maintenance were attractive to this group of individuals. These benefits support the rehabilitation potential of this hearing aid model and its positive impact on the quality of life of older adults in developing countries. TRIAL REGISTRATION: This study was registered under Clinicaltrial.govNCT01902914. Date of registration: July 18, 2013.