标题: | 适用于数位助听器之低复杂度多通道动态范围压缩技术 Complexity-Effective Multi-Channel Dynamic Range Compression (DRC) for Digital Hearing Aids |
作者: | 张巍瀚 Wei-Han Chang 刘志尉 Chih-Wei Liu 电子研究所 |
关键字: | 动态压缩技术;dynamic range compression |
公开日期: | 2008 |
摘要: | 数位助听器由于有相当高的适应性和较为优异的音质表现,已经大幅胜过传统的类比助听器。为了能够调整适合不同听障损害的听力损失,数位助听器必须能根据听障者不同的听觉损失来调整,但不可避免的,复杂的语音讯号处理运算会大幅增加数位助听器的功率消耗;然而,数位助听器的电池续航力一直被使用者所诟病,因此实现高度程式化和降低数位助听器的运算复杂度一直是亟需解决的议题。本论文探讨数位助听器中最关键的运算模组之一:动态范围压缩技术(dynamic range compression; DRC)。以三个通道(Channel/Band)的动态压缩技术为例,传统之动态压缩模组,利用ARM926处理器来实现,约需1,100 MIPS的运算效能才能达到即时(Real-time)的需求。本论文就动态范围压缩技术,从其演算法、架构、以及数值表示上,全方面进行最佳化设计,在不影响音质的条件下,我们提出的演算法实现,可降低传统助听器动态压缩模组约98%的运算量,此低运算复杂度的动态压缩技术可实现于fixed-point或DSP的处理器上。另外,本论文亦提出一基于辅助听力指标(aided audibility index; AAI)的动态范围压缩技术参数调配方法,可搭配医师所开立的处方进行助听器参数的细部调整。最后,上述所有的演算法已实作于一个搭配PC参数调整平台的ARM-based助听器雏型系统中,并完整验证其可行性。 Due to its high flexibility and rather good signal quality, digital hearing aids have made themselves outperform the traditional analog ones. In order to unique fit conditions of individual hearing-impaired people, digital hearing aids must have high level of programmability, which inevitably leads to an increase in power dissipation. However, the short battery lifetime is the most unsatisfactory factor for users. Consequently, improved methods of achieving high programmability as well as low power dissipation are highly desirable for digital hearing aids. This thesis addresses the complexity reduction of dynamic range compression, which is one of the most important modules in digital hearing aids. For the 3-channel DRC on ARM926 processor, the traditional DRC needs more than 1,100 MIPS computing power for real-time 32KHz audio signal processing. In this thesis, we propose a complexity-effective dynamic range compressor (DRC), whose computation is minimized through algorithmic, numerical, and architectural optimizations. The proposed complexity-effective dynamic range compressor saves about 98% computation complexity with the comparable sound quality. Besides, we also propose the complexity-aware parameters adjustment method for DRC based on the Aided Audibility Index (AAI), which can fine-tune the hearing aids parameters with the prescriptions. The feasibility of the proposed complexity-aware DRC has been verified through prototyping on an ARM-based platform, which equips a PC-based hearing aid emulator for parameter selection and evaluation.hearing aids. A complexity-effective dynamic range compressor (DRC) applied in fixed-point or DSP processor, whose computation is minimized through algorithmic, numerical, and architectural optimizations, is proposed. The proposed complexity-effective dynamic range compressor saves about 98% computation complexity with the comparable sound quality. Besides, we also propose the complexity-aware parameters adjustment method for DRC based on the Aided Audibility Index (AAI), which can fine-tune the hearing aids parameters with the prescriptions. The feasibility of the proposed design has been verified through prototyping the complexity-effective compressor on an ARM-based hearing aid prototyping platform, which equips a PC-based emulator for parameter selection and evaluation. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#GT009511636 http://hdl.handle.net/11536/38159 |
显示于类别: | Thesis |