摘 要

随着我国人口老龄化程度日益加重，听力障碍患者迅速增加，对助听技术的需求越来越高。助听系统重点要解决听不到、听不清的问题，这也是检验一个助听系统最终的标准。 本文所研究的基于磁环的助听系统能够使一定范围内布满均匀的磁场，且不会受外界干扰，结合助听器的“T”挡，能很好的帮助患者获取语音信号，非常适合在国内推广。

本文围绕声音处理电路及磁场的设计主要展开以下工作：

（1）信号放大与滤波电路。根据要求合理设计电路形式，由输入输出关系及通带频

率等要求计算出电路各参数及各元件的值。

（2）磁场设计计算与仿真。按照实际使用环境设计线圈形状，用软件进行仿真，计算磁场强度，确定线圈尺寸和电流大小。

（3）助听系统调试。对系统各部分电路分别进行测试以检验是否能正常工作，然后对系统整体进行调试。

（4）噪声分析与设计优化。对噪声来源进行分析，并以此来改进电路的设计。

关键词：磁环；放大电路；语音信号；助听技术

Abstract

With the boom of the aging population in our country, hearing disorders rapidly increase in the demand for hearing aid technology more and more. The focus of the hearing system is to solve the problem, which is not clear, and it is also the final test of a hearing system standards. The hearing aid system based on magnetic studied in this paper can make a certain range covered with homogeneous magnetic field which will not be affected by external interference, and combined with hearing aids’ "T" block, it can be very good to help patients get voice signals and is very suitable for domestic promotion.

In this paper, the design of the sound processing circuit and magnetic field is mainly focused on the following work:

1. Design and calculation of signal amplification and filter circuit. According to the requirements of the rational design of circuit form, the input-output relationship and passband frequency requirement to calculate the value of each parameter and each circuit element.
2. Magnetic field design calculation and simulation. In accordance with the actual use of environmental design coil shape, using simulation software to calculate the magnetic field strength to determine the size of the coil and the current size.
3. Hearing system debugging. The circuit of each part of the system is tested to check whether the normal work, and then debug the system as a whole.
4. Noise analysis and design optimization. According to the actual test results, the noise sources are analyzed for the improvement of the circuit design.

Keywords: magnetic ring; amplifier circuit; speech signal; hearing aid technology

目 录

摘 要···································································I

Abstract·································································II

第1章 绪论 ·····························································1

1.1 研究背景 ·························································1

1.2 研究目的及意义····················································2

1.3 国内外研究现状····················································2

1.4 研究内容及方法····················································3

1.4.1 研究方法·····················································3

1.4.2 研究内容·····················································3

第2章 设计原理 ·························································5

2.1 磁环产生磁场的原理················································5

2.2 助听系统的工作原理················································5

第3章 助听系统设计······················································7

3.1 系统构成·························································7

3.2 磁环的设计························································7

3.2.1 磁场设计要求·················································7

3.2.2 磁场的设计计算···············································8

3.2.3 磁场仿真·····················································9

3.3 前置放大电路设计·················································11

3.3.1 电路设计要求················································12

3.3.2 电路设计计算················································12

3.4 滤波器设计·······················································13

3.4.1 滤波器类型选择···············································13

3.4.2 参数计算与选择···············································13

3.5 功率放大电路设计·················································14

3.5.1 功率放大电路常见问题·········································14

3.5.2 电路设计····················································15

第4章 系统调试与结果分析···············································16

4.1 系统硬件图·······················································16

4.2 系统调试过程·····················································19

4.3 结果分析·························································20

第5章 总结····························································21

参考文献· ······························································22

致谢 ··································································23

第1章 绪论