Development of an automatic matching dual-microphone noise reduction system utilizing TMS320C6713
| Autor: | yan-Ming Yang, 楊彥明 |
|---|---|
| Rok vydání: | 2014 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 102 Previously studies indicated that the adaptive directional microphone strategy has the characteristics of low computing cost and effective noise reduction. By tracking the noise source, this strategy could adaptively change the directivity of the directional dual-microphone to reduce the noise. However, when the two microphones were mismatched, the received signals showed differences on their phases and amplitudes. These differences would decrease the noise reduction performance if this mismatch was not well compensated. The purpose of this study was to add an auto-matching process that matched the dual-microphones to improve the performance of automatic scene classification noise reduction system before the application of the adaptive directional microphone strategy. In this study, we first used Simulink (The MathWorks, Natick, Massachusetts, USA) to simulate the differences in polar directivity of cardioid were resulted from the varied conditions of microphone mismatch, and the auto-matching algorithms compensated the mismatch to achieve the ideal polar directivity of cardioid. Then, the auto-matching algorithms were implemented in TMS320C6713 DSP Starter Kit (Texas Instruments, Dallas, Texas, USA) and compared with the mismatched dual-microphone in the original noise reduction system. The speech reception thresholds (SRTs) from eight normal hearing subjects in different noise conditions were measured with the HINT Pro system (Bio-logic, Chicago, IL, USA) for subjective evaluation. The experimental results showed that the automatic scene classification noise reduction system provided significantly SRT effect and had better speech intelligibility. The perceptual evaluation of speech quality (PESQ) was further used to estimate the quality of speech. Our experimental results showed that the auto-matching dual-microphone system provide more speech quality than those of the original dual-microphone system when the signal-to-noise ratio (SNR) is above 15dB. The PESQ index indicated less distortion of original signals with the auto-matching system. When the SNR is below 15dB, the auto-matching dual-microphone system could discriminate accurately the noise type and decrease the speech distortion caused by the automatic scene classification noise reduction system. The above-mentioned experimental results suggested that auto-matching system not only improve speech intelligibility but also let automatic scene classification noise reduction system obtain more accurate results. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|