Efficient audio signal processing for embedded systems

AdaBoost;Programmable analog circuit;Audio feature selection;Analog classifier;Loudspeaker protection;Sound enhancement

Chiu, Leung Kin ; Electrical and Computer Engineering

University:Georgia Institute of Technology

Department:Electrical and Computer Engineering

关键词: AdaBoost;    Programmable analog circuit;    Audio feature selection;    Analog classifier;    Loudspeaker protection;    Sound enhancement;   

Others  :  https://smartech.gatech.edu/bitstream/1853/44775/1/chiu_leungkin_201208_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

We investigated two design strategies that would allow us to efficiently process audio signals on embedded systems such as mobile phones and portable electronics. In the first strategy, we exploit properties of the human auditory system to process audio signals. We designed a sound enhancement algorithm to make piezoelectric loudspeakers sound "richer" and "fuller," using a combination of bass extension and dynamic range compression. We also developed an audio energy reduction algorithm for loudspeaker power management by suppressing signal energy below the masking threshold. In the second strategy, we use low-power analog circuits to process the signal before digitizing it. We designed an analog front-end for sound detection and implemented it on a field programmable analog array (FPAA). The sound classifier front-end can be used in a wide range of applications because programmable floating-gate transistors are employed to store classifier weights. Moreover, we incorporated a feature selection algorithm to simplify the analog front-end. A machine learning algorithm AdaBoost is used to select the most relevant features for a particular sound detection application. We also designed the circuits to implement the AdaBoost-based analog classifier.