“…The efficacy of user adjustment of amplification has been demonstrated using a variety of protocols that incorporate changes of frequency response (Boothroyd & Mackersie, 2017;Dreschler et al, 2008;Jensen et al, 2019;Keidser & Convery, 2018;Keidser et al, 2008;Mackersie et al, 2019;Nelson et al, 2018). Groupmean user-adjusted frequency responses are generally close to threshold-based prescribed targets (typically within 5 dB), but substantial individual differences have been observed (Jensen et al, 2019;Keidser & Convery, 2018;Mackersie et al, 2019;Nelson et al, 2018;Punch et al, 1994). In addition, Nelson et al (2018) reported that on average, speech recognition outcomes of self-adjusted responses were not significantly different from those using the current version of the National Acoustics Laboratories prescription for Non-Linear hearing aids (NAL-NL2; Keidser et al, 2011).…”