Nonspeech psychophysical tests of spectral resolution, such as the spectral-ripple discrimination task, have been shown to correlate with speech-recognition performance in cochlear implant (CI) users. However, these tests are best suited for use in the research laboratory setting and are impractical for clinical use. A test of spectral resolution that is quicker and could more easily be implemented in the clinical setting has been developed. The objectives of this study were (1) To determine whether this new clinical ripple test would yield individual results equivalent to the longer, adaptive version of the ripple-discrimination test; (2) To evaluate test–retest reliability for the clinical ripple measure; and (3) To examine the relationship between clinical ripple performance and monosyllabic word recognition in quiet for a group of CI listeners.
Twenty-eight CI recipients participated in the study. Each subject was tested on both the adaptive and the clinical versions of spectral ripple discrimination, as well as consonant–nucleus–consonant word recognition in quiet. The adaptive version of spectral ripple used a two-up, one-down procedure for determining spectral ripple discrimination threshold. The clinical ripple test used a method of constant stimuli, with trials for each of 12 fixed ripple densities occurring six times in random order. Results from the clinical ripple test (proportion correct) were then compared with ripple-discrimination thresholds (in ripples per octave) from the adaptive test.
The clinical ripple test showed strong concurrent validity, evidenced by a good correlation between clinical ripple and adaptive ripple results (r = 0.79), as well as a correlation with word recognition (r = 0.7). Excellent test–retest reliability was also demonstrated with a high test–retest correlation (r = 0.9).
The clinical ripple test is a reliable nonlinguistic measure of spectral resolution, optimized for use with CI users in a clinical setting. The test might be useful as a diagnostic tool or as a possible surrogate outcome measure for evaluating treatment effects in hearing.
The clinical ripple test assesses spectral resolution and is designed to be administered clinically with cochlear implant users. This study reports on its development and validation. The test uses a method of constant stimuli, and performance is quantified as overall proportion correct. Twenty-eight cochlear implant users were tested with the clinical ripple test, an adaptive ripple discrimination test, and word recognition. Good correlations were obtained between the ripple measures and word recognition. Excellent test–retest reliability was demonstrated. The clinical ripple test appears to be a valid and reliable instrument for clinical assessment of cochlear implant recipients.
1VM Bloedel Hearing Research Center, Department of Otolaryngology, University of Washington, Seattle, Washington, USA; 2Envoy Medical Corp., St. Paul, Minnesota, USA; and 3Department of Audiology and Speech Pathology, University of Tennessee Health Science Center, Knoxville, Tennessee, USA.
The authors declare no other conflict of interest.
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