Carlsson P, Håkansson B, Ringdahl A
Department of Applied Electronics, Chalmers University of Technology, Göteborg, Sweden.
J Acoust Soc Am. 1995 Feb;97(2):1124-9. doi: 10.1121/1.412225.
The bone-anchored hearing aid is connected, by means of a skin-penetrating bayonet coupling, to an implanted titanium fixture. Hence, direct bone conduction (dbc) excitation is used. Since no international standard of audiometric zero for dbc force threshold exists, it is of general interest to determine the dbc force threshold for normal hearing subjects. Two different methods have previously been applied to estimate the relation between bone conduction (bc) and dbc thresholds. One preliminary problem was to make a measurement of the output-force level of dbc transducers, which is equivalent to the situation in situ. A skull simulator, TU-1000, has been designed for measuring the output-force level of dbc transducers. The skull simulator does, in an adequate way, reflect the mechanical point impedance of the human skull. This opportunity to determine equivalent dbc force thresholds has motivated the present study in which a linear relation between the dbc force threshold and the bc force threshold was estimated. The estimate found in the present study conforms fairly well with the two previously found estimates. It is suggested that the estimate found in the present study be used as the reference equivalent threshold force level for dbc.
骨锚式助听器通过一种穿透皮肤的卡口式连接器与植入的钛制固定装置相连。因此，采用了直接骨传导（dbc）激励方式。由于不存在针对dbc力阈值的听力零级国际标准，确定正常听力受试者的dbc力阈值具有普遍意义。此前已应用两种不同方法来估计骨传导（bc）阈值与dbc阈值之间的关系。一个初步问题是测量dbc换能器的输出力水平，这等同于原位情况。已设计出一种颅骨模拟器TU - 1000用于测量dbc换能器的输出力水平。该颅骨模拟器能够充分反映人类颅骨的机械点阻抗。确定等效dbc力阈值的这一机会促使了本研究的开展，在本研究中估计了dbc力阈值与bc力阈值之间的线性关系。本研究中得到的估计结果与之前发现的两个估计结果相当吻合。建议将本研究中得到的估计结果用作dbc的参考等效阈值力水平。
