Han Woojae, Kim Noori
Laboratory of Hearing and Technology, Division of Speech Pathology and Audiology, Research Institute of Audiology and Speech Pathology, College of Natural Sciences, Hallym University, Chuncheon, Korea.
Department of Electrical and Computer Engineering, DigiPen Institute of Technology Singapore, Singapore.
J Audiol Otol. 2018 Jul;22(3):111-119. doi: 10.7874/jao.2018.00073. Epub 2018 Jun 14.
The hearing-aid transducer is ubiquitous in the hearing-aid industry. For example, the balanced armature receiver (BAR), first invented by A.G. Bell, has been used in all telephone earphones because it has the highest output and best frequency response. Nevertheless, previous electro-mechanical studies on these miniature speakers are quite primitive, given the price of the transducers. Thus, more detailed analysis is critically important for the field of hearing science. This review study was motivated by Hunt's parameter calibration (1954), a widely used commercial hearing-aid receiver (ED series, manufactured by Knowles Electronics, Inc.). In the body of the study, the transfer function of the BAR system (i.e., pressure over voltage) was calculated from Hunt's parameters, solely from the electrical terminals of the device. The computed transfer function was then further investigated by comparing to the pole-zero fitting method using the methods of Gustavsen and Semlyen (1999) and Prony (1975). Based on our short experiment, the better fitting result was achieved with Gustavsen and Semlyen's method. By decomposing results of the transfer function fitting into all-pass and minimum-phase parts, the system was confirmed as a delay system. We conclude that the BAR system is linear, time-invariant, stable, and causal while providing an evidencebased understanding of the hearing-aid receiver system.
助听器换能器在助听器行业中无处不在。例如，由A.G.贝尔首次发明的平衡电枢接收器（BAR），因其具有最高的输出和最佳的频率响应，已被用于所有的电话耳机中。然而，鉴于这些换能器的价格，以往对这些微型扬声器的机电研究相当原始。因此，更详细的分析对听力科学领域至关重要。本综述研究的动机来自于亨特的参数校准（1954年），这是一种广泛使用的商业助听器接收器（ED系列，由诺尔斯电子公司制造）。在研究主体部分，BAR系统的传递函数（即压力与电压之比）仅从设备的电气端子出发，根据亨特的参数进行计算。然后，通过与古斯塔夫森和塞姆林（1999年）以及普龙尼（1975年）的方法进行零极点拟合方法相比较，对计算出的传递函数进行进一步研究。基于我们的简短实验，古斯塔夫森和塞姆林的方法获得了更好的拟合结果。通过将传递函数拟合的结果分解为全通部分和最小相位部分，该系统被确认为一个延迟系统。我们得出结论，BAR系统是线性、时不变、稳定且因果的，同时为助听器接收器系统提供了基于证据的理解。
