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[The artifacts and test-retest reliability of multiple auditory steady-state response].

OBJECTIVE
To investigate the characteristics and clinical application of artifacts and the test-retest reliability of multiple auditory steady-state response (MASSR).


METHOD
The authors tested a group of healthy young volunteers and a group of patients with sensory hearing loss with the MASSR by analysing the rate of false negative artifacts (FNA) and their distribution. The healthy young volunteers were retested with MASSR several days after the first test to investigated the test retest reliability of MASSR. Furthermore, three cases of healthy young volunteers were retested in the sleeping status to explore the stability of MASSR threshold and the influence of sleep.


RESULT
(1) The FNA mainly distributed in low frequencies districts and the intensities were near threshold, no remarkable differences could be seen between the normal ears and the ear with sensory hearing loss. The FNA disappeared when the volunteers were asleep. (2) The test-retest variability was much higher in 0.5 kHz than in other frequencies. The variable range was 0 - 30 dB in 0.5 kHz, and there was test-retest reliability in 1.0-4.0 kHz. (3) The artificial response was present when using strong stimulus for the patients with profound hearing loss. When MASSR was recorded in awake condition, the FNA appeared. When using strong stimulus for the cases with profound hearing loss, the artificial response existed and the test-retest variabilities were large. The whole test duration was often much longer than the auditory brainstem response (ABR) and 40 Hz auditory evoked potential (40 Hz AEP).


CONCLUSION
As an objective auditory evaluation method, MASSR scarcely has superior characteristics to ABR and 40 Hz AEP.