Detection of Nonstationary Noise and Improved Voice Activity Detection in an Automotive Hands-free Environment

Speech processing in the automotive environment is a challenging problem due to the pres-ence of powerful and unpredictable nonstationary noise. This thesis addresses two detection problems involving both nonstationary noise signals and nonstationary desired signals. Two detectors are developed: one to detect passing vehicle noise in the presence of speech and one to detect speech in the presence of passing vehicle noise. The latter is then measured against a state-of-the-art voice activity detector used in telephony. The process of compiling a library of recordings in the automobile to facilitate this research is also detailed. ACKNOWLEDGEMENTS I owe a great deal of thanks to very many people for making my graduate work possible and enjoyable. I’d like to start by thanking my parents for their unwavering support and generous encouragement throughout my academic career and entire life. I’m certain I could not have gotten this far without it. Next I’d like to thank Rick Brown for his commitment, encouragement, assistance and company over an intense three years of electrical and computer engineering. I owe two o