Salonna I, Bartoli R, Galizia R, Quaranta A
Centro di Audiologia e Otologia, Università degli Studi di Bari.
Boll Soc Ital Biol Sper. 1992 Nov;68(11):715-20.
In order to evaluate the central interferences on the auditory efficiency, the effect of contralateral masking noise on Critical Ratio (CR) has been studied in 14 normal ears (control group), in 12 ears with cochlear disorders and in 6 with retrocochlear lesion (acoustic neuromas); in all cases the impairment was unilateral, while the other ear was normal. CR values were calculated for 1 KHz pulsed tones (duration 500 ms, rise/fall 25 ms, duty cycle of 50%); the masking noise was a wide band (90-20,000 Hz) delivered at 40 dB SL. The results have demonstrated that in the presence of contralateral masking noise, CRs don't modify both in the normal ears and in those with retrocochlear disorder, whereas they increase, almost always, in ears with cochlear deafness. These results demonstrate that the involvement of central auditory pathways, because of contralateral noise, makes the auditory efficiency worse, only in ears with cochlear dysfunctions; this behaviour seems to confirm the peripheral origin of CR.
为了评估中枢干扰对听觉效率的影响，研究了对侧掩蔽噪声对14只正常耳（对照组）、12只患有耳蜗疾病的耳朵以及6只患有蜗后病变（听神经瘤）的耳朵的临界比率（CR）的影响；在所有情况下，损伤均为单侧，而另一只耳朵正常。计算了1kHz脉冲音（持续时间500ms，上升/下降25ms，占空比50%）的CR值；掩蔽噪声为40dB SL下的宽带（90 - 20,000Hz）。结果表明，在存在对侧掩蔽噪声的情况下，正常耳和患有蜗后疾病的耳朵的CR均未改变，而在患有耳蜗性耳聋的耳朵中，CR几乎总是增加。这些结果表明，由于对侧噪声导致的中枢听觉通路受累，仅在患有耳蜗功能障碍的耳朵中会使听觉效率变差；这种行为似乎证实了CR的外周起源。
