Department of Otorhinolaryngology and Head and Neck Surgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands.
Int J Audiol. 2024 Jul;63(7):527-534. doi: 10.1080/14992027.2023.2208288. Epub 2023 May 11.
In standards IEC 60645-1 and ANSI S3.6, the free-field equivalent earphone output level method is assumed as the reference for speech audiometry. Three calibration procedures for this method were compared in this study.
Speech audiometry was conducted with Dutch consonant-vowel-consonant words for the following conditions: 1. TDH39 earphones, 2. loudspeaker, and 3. free-field simulated with TDH39 earphones. The first calibration procedure was based on the empirically determined difference between the speech recognition threshold (SRT) with earphones and a loudspeaker. The second procedure was based on the theoretical free-field correction, derived from the known speech spectrum and the free-field to coupler difference. The third calibration procedure corresponded to the results of the free-field simulated speech material under earphones.
The sample included 20 normal hearing subjects.
The differences between the observed SRT in the free-field and earphone conditions and the free-field and simulated free-field conditions were 7.1 dB and 0.6 dB, respectively.
The three calibration procedures for the free-field equivalent output method yielded approximately the same results, and therefore all appear to be useful for TDH39 earphones.
在标准 IEC 60645-1 和 ANSI S3.6 中，自由场等效耳机输出电平法被假定为言语测听的参考。本研究比较了该方法的三种校准程序。
使用荷兰辅音-元音-辅音词进行言语测听，条件如下：1. TDH39 耳机，2. 扬声器，3. 用 TDH39 耳机模拟自由场。第一种校准程序基于耳机和扬声器的语音识别阈值（SRT）之间的经验确定差异。第二种程序基于从已知语音频谱和自由场到耦合器差异推导出来的理论自由场校正。第三种校准程序对应于耳机下模拟自由场语音材料的结果。
样本包括 20 名正常听力受试者。
自由场和耳机条件以及自由场和模拟自由场条件下观察到的 SRT 之间的差异分别为 7.1dB 和 0.6dB。
自由场等效输出方法的三种校准程序产生了大致相同的结果，因此对于 TDH39 耳机来说，所有这些方法似乎都有用。
