BACKGROUND : Speech-in-noise tests have become a valuable part of the audiometric test battery
providing an indication of a listener’s ability to function in background noise. A simple digitsin-
noise (DIN) test could be valuable to support diagnostic hearing assessments, hearing aid
fittings and counselling for both paediatric and adult populations.
OBJECTIVE : The objective of this study was to evaluate the South African English smartphone
DIN test’s performance as part of the audiometric test battery.
DESIGN : This descriptive study evaluated 109 adult subjects (43 male and 66 female subjects)
with and without sensorineural hearing loss by comparing pure-tone air conduction thresholds,
speech recognition monaural performance scores (SRS dB) and the DIN speech reception
threshold (SRT). An additional nine adult hearing aid users (four male and five female subjects)
were included in a subset to determine aided and unaided DIN SRTs.
RESULTS : The DIN SRT is strongly associated with the best ear 4 frequency pure-tone average
(4FPTA) (rs = 0.81) and maximum SRS dB (r = 0.72). The DIN test had high sensitivity and
specificity to identify abnormal pure-tone (0.88 and 0.88, respectively) and SRS dB (0.76 and
0.88, respectively) results. There was a mean signal-to-noise ratio (SNR) improvement in the
aided condition that demonstrated an overall benefit of 0.84 SNR dB.
CONCLUSION : The DIN SRT was significantly correlated with the best ear 4FPTA and maximum
SRS dB. The DIN SRT provides a useful measure of speech recognition in noise that can
evaluate hearing aid fittings, manage counselling and hearing expectations.