Department of Electrical Engineering, Hearing Systems, Technical University of Denmark, Lyngby, Denmark.
Int J Audiol. 2011 Jun;50(6):361-6. doi: 10.3109/14992027.2010.551787. Epub 2011 Feb 7.
This paper reports free-field correction values for the Interacoustics DD 45 audiometric earphone. The free-field correction values for earphones provide the loudness based equivalence to loudspeaker presentation. Correction values are especially used for the calibration of audiometric equipment for speech audiometry performed with headphones. Calibration values may be found in, e.g. the ISO 389 series of standards.
The free-field correction values were determined by means of loudness balance measurements of one-third octave noises (centre frequencies 125 Hz to 8000 Hz) presented alternately from a loudspeaker in a free field and from the earphones. The procedure was essentially in accordance with the free-field frequency response procedure described in IEC 60268-7: Headphones and earphones.
Four earphones and 14 test subjects.
Free field correction values are reported for the acoustic coupler IEC 60318-3 (NBS 9-A) and for the ear simulator IEC 60318-1. The results are in good agreement with the results of another independent investigation.
The reported free-field correction values may be used as part of the basis for future standardization of the DD 45 earphone.
本文报告了 Interacoustics DD 45 测听耳机的自由场校正值。耳机的自由场校正值提供了与扬声器呈现相对应的响度等效值。校正值特别用于校准使用耳机进行言语测听的测听设备。校准值可以在例如 ISO 389 系列标准中找到。
通过在自由场中从扬声器和耳机交替呈现三分之一倍频程噪声（中心频率为 125 Hz 至 8000 Hz）的响度平衡测量来确定自由场校正值。该程序基本上符合 IEC 60268-7 中描述的自由场频率响应程序：耳机。
四个耳机和 14 个测试对象。
为 IEC 60318-3（NBS 9-A）声学耦合器和 IEC 60318-1 耳模拟器报告了自由场校正值。结果与另一个独立调查的结果非常吻合。
报告的自由场校正值可用作未来 DD 45 耳机标准化的基础的一部分。
