[Correlation of subjective and objective methods of evaluating hearing threshold].

INTRODUCTION: Objective evaluation of hearing threshold and detection of hearing impairment are the basic prerequisites for hearing and speech rehabilitation. In infants and early pre-school children tonal audiometry is not possible. Though subjective, tonal audiometry is the most reliable method for evaluation of hearing threshold. Therefore, in children of this age, hearing threshold is evaluated by objective electroacoustic methods: early brainstem auditory evoked potentials (BAEP) and acoustic stapedius reflex. MATERIAL AND METHODS: In 60 adult examinees (120 ears) with normal hearing we analyzed the correlation between biological hearing threshold determined by tonal audiometry and threshold of ipsilateral stapedius reflex, as well as response threshold determined by brainstem evoked response audiometry (BERA). RESULTS AND DISCUSSION: We found a statistically significant correlation between biological hearing threshold and response threshold evaluated by brainstem evoked response audiometry. The linear Pearson correlation coefficient of: r = 0.40 for 500 Hz, r = 0.41 for 1,000 Hz, r = 0.44 for 2,000 Hz and r = 0.43 for 4,000 Hz (p < 0.01 for all values). Correlation coefficients between the biological hearing threshold and ipsilateral stapedius reflex threshold were not significant for 500 Hz (r = 0.46) and 1,000 Hz (r = 0.082), negative correlation was found for 2,000 Hz (r = 0.2656, p < 0.05) and significant correlation was confirmed only for 4,000 Hz (r = 0.225, p < 0.05). CONCLUSION: In regard to evident reliability of objective evaluation of hearing threshold by brainstem evoked response audiometry, this paper also suggests correction factors for evaluation of biological hearing threshold, and lists the deficiencies of hearing threshold assessment by this--still most accurate electrophysiological method.