Do we need audiogram-based prescriptions? A systematic review

Objective Hearing aids are typically programmed using the individual's audiometric thresholds and verified using real-ear measures. Developments in technology have resulted in a new category of direct-to-consumer devices, which are not necessarily programmed using the individual's audiometric thresholds. This review aimed to identify whether programming hearing aids using the individual's validated audiogram-based prescription, and verified using real-ear measures, results in better outcomes for adults with hearing loss. Design The review was registered in PROSPERO and reported in accordance with PRISMA guidelines. Study sample After screening more than 1370 records, seven experimental studies met the eligibility criteria. Results Studies were categorised under three methods of fitting: (i) comparative fitting evaluating different settings based on the beliefs of the audiologist; (ii) client choice of preset responses; and (iii) self-fit by adjustment. The findings suggest that using a prescription based on the individual's audiogram improves outcomes relative to the comparative and client choice fitting approaches. Self-adjustment during daily use may produce equivalent (or better) outcomes than an audiogram-based prescription. The quality of evidence for the outcomes ranged from low to very low. Conclusions This review has highlighted the dearth of high-quality studies on which to make evidence-based decisions on hearing aid fitting methods.