Olsen W O, Noffsinger D
Ann Otol Rhinol Laryngol. 1976 Nov-Dec;85(6 PT. 1):820-5. doi: 10.1177/000348947608500611.
Masking level differences (MLD) for 500 Hz pure tones and for spondees were obtained from 48 subjects. Twelve were without otologic or neurologic complaints (normal), 12 had high frequency, noise-induced hearing losses, 12 were diagnosed otologically as having Ménière's disorder, and 12 had neurologically diagnosed central nervous system (CNS) disorders. Results indicated that high frequency, noise-induced hearing losses do not affect MLD for 500 Hz stimuli, but do diminish the size of MLD for speech. Masking level differences for both 500 Hz and spondees were decreased for the Ménière's disorder group. The group of patients having CNS disorders attributed to multiple sclerosis, to inflammatory lesion of the pons, to degenerative processes of the cerebellum and adjacent nervous tissue, or to brain stem cerebrovascular accident had normal hearing according to conventional pure tone and speech testing, but attained smaller than normal MLD for 500 Hz and spondees. These findings agree closely with results obtained in an earlier study and continue to suggest that, given normal peripheral auditory function, MLD tests may have unique value in detection of subtle lesions of the central auditory nervous system.
从48名受试者那里获得了500赫兹纯音和扬扬格词的掩蔽级差（MLD）。其中12人无耳科或神经科主诉（正常），12人有高频噪声性听力损失，12人经耳科诊断患有梅尼埃病，12人经神经科诊断患有中枢神经系统（CNS）疾病。结果表明，高频噪声性听力损失不影响500赫兹刺激声的MLD，但会减小言语的MLD大小。梅尼埃病组的500赫兹和扬扬格词的掩蔽级差均降低。患有因多发性硬化症、脑桥炎性病变、小脑及邻近神经组织退行性病变或脑干脑血管意外所致中枢神经系统疾病的患者组，根据传统纯音和言语测试听力正常，但500赫兹和扬扬格词的MLD小于正常。这些发现与早期研究结果密切相符，并继续表明，在外周听觉功能正常的情况下，MLD测试在检测中枢听觉神经系统细微病变方面可能具有独特价值。
