%0 Journal Article
%T Discrimination of Gain Increments in Speech-Shaped Noises
%A Benjamin Caswell-Midwinter
%A William M. Whitmer
%J Archive of "Trends in Hearing".
%D 2019
%R 10.1177/2331216518820220
%X Frequency-dependent gain adjustments are routine in hearing-aid fittings, whether in matching to real-ear targets or fine-tuning to patient feedback. Patient feedback may be unreliable and fittings inefficient if adjustments are not discriminable. To examine what gain adjustments are discriminable, we measured the just-noticeable differences (JNDs) for level increments in speech-shaped noises processed with prescription gains. JNDs were measured in the better ears of 38 participants with hearing impairment using a fixed-level, same-different task. JNDs were measured for increments at six individual frequency-bands: a 0.25-kHz low-pass band; octave-wide bands at 0.5, 1, 2, and 4£¿kHz; and a 6-kHz high-pass band. JNDs for broadband increments were also measured. JNDs were estimated at d¡¯ of 1 for a minimally discriminable increment in optimal laboratory conditions. The JND for frequency-band increments was 2.8£¿dB excluding the 0.25-kHz low-pass band, for which the JND was 4.5£¿dB. The JND for broadband increments was 1.5£¿dB. Participants¡¯ median frequency-band and broadband JNDs were positively correlated. JNDs were mostly independent of age, pure-tone thresholds, and cognitive score. In consideration of self-fitting adjustments in noisier conditions, JNDs were additionally estimated at a more sensitive d¡¯ of 2. These JNDs were 6£¿dB for bands below 1£¿kHz, and 5£¿dB for bands at and above 1£¿kHz. Overall, the results suggest noticeable fine-tuning adjustments of 3£¿dB and self-fitting adjustments of 5£¿dB
%K just-noticeable differences
%K hearing aids
%K hearing-aid gain
%K hearing-aid fitting
%U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6351966/