New instrumentation for automated tinnitus psychoacoustic assessment.

CONCLUSION: Although tinnitus is a major health problem, techniques to quantify its perceptual aspects are not standardized. This study represents a key step in our efforts to develop clinical methodology to accurately and reliably quantify the sensation of tinnitus, using a uniform method for obtaining a battery of tinnitus measures. OBJECTIVES: The purpose of this study was to evaluate the performance of the automated system, which was redesigned to reduce time of testing and to add new testing capabilities. The primary difference in function was the use of a 'knob' device that enabled patient control of auditory stimuli. The new tests included assessment of minimum masking level (MML) and residual inhibition (RI). MATERIALS AND METHODS: As with previous iterations of the system, a computer program ran all testing and subjects read instructions and provided responses via a computer touch-screen. Three separate studies were conducted. Study 1 evaluated within- and between-session test-retest response reliability of tinnitus loudness matches (LMs) and pitch matches (PMs). Study 2 was conducted to evaluate differences in LMs and PMs between subjects with and without tinnitus - to obtain pilot data to assist in the development of a test for 'tinnitus malingering.' Study 3 evaluated the system's capability of obtaining MMLs and RI as well as the between-session reliability of these measures. RESULTS: Study 1 documented that the new system could obtain LMs and PMs within approximately 20 min, while maintaining clinically acceptable reliability. Study 2 revealed characteristic differences in LM and PM test results for individuals who did not experience tinnitus. Study 3 documented the system's ability to obtain measures of MML and RI that were reliable across sessions.

Comparison of two computer-automated procedures for tinnitus pitch matching.

Clinical assessment of the perceptual characteristics of tinnitus usually includes an attempt to match the pitch of tinnitus to a pure tone. A standardized clinical protocol for tinnitus pitch matching does not yet exist, and there is a history of unsuccessful attempts to obtain such measures reliably. The present study was designed to evaluate new protocols for identifying the perceived pitch of tinnitus, with the objectives of reducing testing time and improving test-retest reliability. Two protocols ("Octave" and "Binary") were developed, each of which was patterned after the testing procedure previously developed at the Oregon Tinnitus Clinic and used to assess thousands of tinnitus patients. Both protocols use computer-automation to conduct testing; the protocols differ according to their specific testing algorithms. Twenty subjects with nonfluctuating tinnitus were each tested over two sessions. Results of testing revealed that both protocols could obtain pitch matches within 20 to 25 min. Reliability of responses was good for some subjects but not others, and the Binary protocol generally provided more reliable results.

Reliability of hearing thresholds: computer-automated testing with ER-4B Canal Phone earphones.

This study was conducted to document test-retest reliability of hearing thresholds using our computer-automated tinnitus matching technique and Etymotic ER-4B Canal Phone insert earphones. The research design involved repeated threshold measurements both within and between sessions, and testing to evaluate the potential effect of eartip removal and reinsertion. Twenty normal-hearing subjects were evaluated over two testing sessions with the use of a fully automated protocol for determining thresholds with 1-dB precision. Thresholds were first obtained at 0.5-16.0 kHz, in one-third octave frequency steps (16 test frequencies). The octave frequencies were then retested, first without removing the eartips, then after eartip removal and replacement. Responses between sessions differed by an average of 2.5 dB across all 16 test frequencies, and 91.5 percent of the repeated thresholds varied within +/-5 dB (98.1 percent within +/-10 dB). Reliability of within-sessions thresholds was also good, and there was no effect of eartip removal and replacement.

Computer-automated clinical technique for tinnitus quantification.

This study addresses the need for uniformity in techniques for clinical quantification of tinnitus. Because automation can be an effective means to achieve standardization, this laboratory is developing techniques to perform computer-automated tinnitus testing. The present study was conducted to demonstrate the feasibility of obtaining reliable tinnitus measures using a fully automated system. A computer-controlled psychoacoustical system was developed to quantify tinnitus loudness and pitch using a tone-matching technique. Hearing thresholds were also obtained as part of the procedure. The system generated test stimuli and simultaneously controlled a notebook computer positioned in the sound chamber facing the patient. The notebook computer displayed instructions for responding and relayed response choices through on-screen "buttons" that the patient touched with a pen device. Twenty individuals with tinnitus were evaluated with the technique over two sessions, and responses were analyzed for test-retest reliability. Analyses revealed good reliability of thresholds, loudness matches, and pitch matches. These results demonstrate that use of a fully automated system to obtain reliable measurements of tinnitus loudness and pitch is feasible for clinical application.

Reliability of tinnitus loudness matches under procedural variation.

Repeated tinnitus loudness matches (LMs) were obtained to determine response reliability using a computer-automated technique with two procedural variations, fixed or random step sizes, to increase output level during the initial ascending series of tones at each frequency. Twenty subjects with stable, tonal tinnitus were evaluated with both methods during each of two sessions. Response instructions were displayed on a portable computer, and a pen device was used to make response choices that appeared on the touch-sensitive video monitor. For each method, hearing thresholds and LMs were obtained, with 1-dB resolution, at 1/3-octave frequencies from 1 to 16 kHz. Analyses revealed reliability of LMs to be equivalent between methods. LM data are reported in both dB SPL and dB SL, with the SPL values providing greater reliability both within and between sessions (all r's > or = .889, p's < or = .0001).