Department of Experimental Psychology, University of Cambridge, Downing Street, Cambridge, CB2 3EB, United Kingdom.
J Acoust Soc Am. 2012 Jun;131(6):4722-31. doi: 10.1121/1.3699233.
Frequency modulation detection limens (FMDLs) were measured for five hearing-impaired (HI) subjects for carrier frequencies f(c) = 1000, 4000, and 6000 Hz, using modulation frequencies f(m) = 2 and 10 Hz and levels of 20 dB sensation level and 90 dB SPL. FMDLs were smaller for f(m) = 10 than for f(m) = 2 Hz for the two higher f(c), but not for f(c) = 1000 Hz. FMDLs were also determined with additional random amplitude modulation (AM), to disrupt excitation-pattern cues. The disruptive effect was larger for f(m) = 10 than for f(m) = 2 Hz. The smallest disruption occurred for f(m) = 2 Hz and f(c) = 1000 Hz. AM detection thresholds for normal-hearing and HI subjects were measured for the same f(c) and f(m) values. Performance was better for the HI subjects for both f(m). AM detection was much better for f(m) = 10 than for f(m) = 2 Hz. Additional tests showed that most HI subjects could discriminate temporal fine structure (TFS) at 800 Hz. The results are consistent with the idea that, for f(m) = 2 Hz and f(c) = 1000 Hz, frequency modulation (FM) detection was partly based on the use of TFS information. For higher carrier frequencies and for all carrier frequencies with f(m) = 10 Hz, FM detection was probably based on place cues.
为了测量五个听力受损（HI）受试者的频率调制检测极限（FMDL），我们使用调制频率 f(m) = 2 Hz 和 10 Hz 以及 20 dB 感觉级和 90 dB SPL 的载波频率 f(c) = 1000 Hz、4000 Hz 和 6000 Hz。对于两个较高的 f(c)，f(m) = 10 Hz 的 FMDL 比 f(m) = 2 Hz 的 FMDL 小，但对于 f(c) = 1000 Hz 则不然。还确定了具有附加随机幅度调制（AM）的 FMDL，以破坏激励模式线索。对于 f(m) = 10 Hz 的破坏效应大于 f(m) = 2 Hz 的破坏效应。f(m) = 2 Hz 和 f(c) = 1000 Hz 的最小干扰发生。还测量了正常听力和 HI 受试者对于相同 f(c)和 f(m)值的 AM 检测阈值。对于两个 f(m)，HI 受试者的性能都更好。对于 f(m) = 10 Hz 的 AM 检测要好得多，而对于 f(m) = 2 Hz 的 AM 检测则要差得多。其他测试表明，大多数 HI 受试者可以区分 800 Hz 的时间精细结构（TFS）。结果与以下观点一致，即对于 f(m) = 2 Hz 和 f(c) = 1000 Hz，频率调制（FM）检测部分基于 TFS 信息的使用。对于更高的载波频率和所有载波频率 f(m) = 10 Hz，FM 检测可能基于位置线索。
