Context-Aware Sound Field Enhancement for Headphones

• Main Authors: YING-SHENG YANG, 楊穎昇
• Other Authors: Oscal T.-C. Chen
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/46604396523608511808

碩士 === 國立中正大學 === 電機工程研究所 === 101 === In this thesis, we proposed a technique of context-aware acoustic field enhancement under a listening condition using a stereo headphone. The architecture consists of three parts which are blind audio separation, acoustic field enhancement and virtual bass enhancement. In the blind audio separation system, we use commercial audio tracks’ mixture mathematical characteristics of left and right channels to carry out time-frequency binary mask, and then separate dominate sound (vocal and dialogues) and subordinate sound (incidental music and surrounding sound). In the acoustic field enhancement system, based on different audio property, we provide appropriate enhancers as follows: In the incidental music part, reduce left and right channels’ correlation to achieve externalization, decrease listening fatigue and expand the acoustic sound field as more as possible. In the speech part, we utilize an equalizer to enhance the consonants’ frequency bands, to achieve speech intelligibility. In the vocal part, the full search of two delay impulses at a time domain is conducted at difference critical bands, in order to make the vocal with the accompaniment more matchable. Finally, considering the physical characteristic of headphones, we adopt the missing fundamental phenomenon to enhance low frequency bands. The experimental results reveal that our method can make the dominate sound of movie audio more transparency compare with conventional acoustic field enhancement method. Summing of the above three systems, our method present excellent sound-field spaciousness, clear dialog, deep bass and immersive surrounding sense. Keywords：Blind Audio Separation, De-correlation, Externalization, Virtual Bass Enhancement, Speech Intelligibility Enhancement