Matthew Maciejewski is a Research Scientist with the Human Language Technologies Center of Excellence. Previously, he was a Research Scientist in the Alexa division of Amazon, working on Acoustic Event Detection. He received his Ph.D. in Electrical and Computer Engineering from Johns Hopkins University at the Center for Language and Speech Processing, advised by Sanjeev Khudanpur and Shinji Watanabe. He also received a M.S. from Johns Hopkins University, as well as a B.S. from Carnegie Mellon University. His research interests are centered on speech and audio processing, including speaker diarization and source separation and enhancement.