En studie av skillnader mellan monotisk och dikotisk 40 Hz Auditory Steady-State Response

Abstract

Objective The objective of this study was to investigate differences between monotich and dichotic 40 Hz Auditory Steady-State Response (ASSR) with Interacoustics Eclipse. Design The aspects studied are test duration, relation be¬tween ASSR and behavioural thresholds (BT), reproducibility and correlation between rejects during Brainstem Response Audiometry (BRA) and differences between ASSR and BT. Monotic and dichotic ASSR-thresholds for eight normal hearing subjects (<20 dB HL) were estimated for frequencies 0.5, 1, 2 and 4 kHz. The results were analyzed by mean and standard deviation. Results Duration: The analyze show that dichotic is the measurement that has the shortest test duration if both ears are to be tested at four frequencies. Relation between ASSR and BT: No difference between monotic measurement (MM) and dichotic measurement (DM) could be distinguished. How¬ever the results show that the correlation between ASSR and BT is greatest at 1 kHz. Reproducibility: Neither MM or DM show ASSR-thresholds that are generally better. Best reproducibility is found at 2 and 4 kHz. Correlation between rejects during BRA and dif¬ferences between ASSR and BT: A possible connection can only be seen at 0.5 kHz. Conclusion The results of this study show that DM is preferable when the test time is reduced without affecting the result. For a generally applicable result more extensive studies should be made.