Fitting hearing aids using clinical prefitting speech measures: an evidence-based review.

A systematic review of the literature addressed the question "Is there evidence of a good correlation between unaided prefitting speech measures and aided satisfaction on self-report measures?" This restricted question is only one of several possible questions related to speech measures and hearing aid fittings. The levels of evidence that were accepted included meta-analyses, randomized controlled trials, and nonrandomized intervention studies. Nearly 300 articles and book chapters were identified during the initial search; 220 were eliminated on the basis of their abstracts; and 80 papers and book chapters were reviewed in depth. Five studies met the criteria set forth in this review. No significant correlation between traditional unaided prefitting speech measures and aided satisfaction was found in any of the five studies. One of the studies showed a correlation between the results of a prefitting speech-in-noise test and self-reported aided satisfaction.

Development of a quick speech-in-noise test for measuring signal-to-noise ratio loss in normal-hearing and hearing-impaired listeners.

This paper describes a shortened and improved version of the Speech in Noise (SIN) Test (Etymotic Research, 1993). In the first two of four experiments, the level of a female talker relative to that of four-talker babble was adjusted sentence by sentence to produce 50% correct scores for normal-hearing subjects. In the second two experiments, those sentences-in-babble that produced either lack of equivalence or high across-subject variability in scores were discarded. These experiments produced 12 equivalent lists, each containing six sentences, with one sentence at each adjusted signal-to-noise ratio of 25, 20, 15, 10, 5, and 0 dB. Six additional lists were also made equivalent when the scores of particular pairs were averaged. The final lists comprise the "QuickSIN" test that measures the SNR a listener requires to understand 50% of key words in sentences in a background of babble. The standard deviation of single-list scores is 1.4 dB SNR for hearing-impaired subjects, based on test-retest data. A single QuickSIN list takes approximately one minute to administer and provides an estimate of SNR loss accurate to +/-2.7 dB at the 95% confidence level.