Speech Communication Laboratory



About SCL


Carol Espy-Wilson

Director, Speech Communication Lab

email : espy AT isr DOT umd DOT edu

Dr. Carol Espy-Wilson is a Professor in the Electrical and Computer Engineering Department and the Institute for Systems Research at the University of Maryland.

Dr. Espy-Wilson received a B.S. in Electrical Engineering from Stanford University in 1979, and a M.S., E.E. and Ph.D. in Electrical Engineering from the Massachusetts Institute of Technology in 1981, 1984 and 1987, respectively. Prior to joining the faculty at the University of Maryland, Dr. Espy-Wilson was a faculty member at Boston University.

Dr. Espy-Wilson's research is in speech communication. She combines knowledge of digital signal processing, speech science, linguistics and acoustic phonetics to conduct interdisciplinary research in speech recognition, speech production, speaker recognition and speech enhancement. Specific research projects include the development of (a) a speech signal representation that contains only linguistic information, (b) the a speech signal representation that highlights speaker characteristics, (c) a probabilistic framework for an event-based speech recognition system, (d) supervised and unsupervised acoustic models for speaker recognition and (e) vocal tract models of complex speech sounds.

Dr. Espy-Wilson has authored or coauthored numerous papers in journals, conference proceedings and books. She is a Fellow of the Acoustical Society of America (ASA) and a Member of the Institute for Electrical and Electronic Engineers (IEEE). Among the honors and awards she has received for her research contributions are the Clare Boothe Luce Professorship in 1990, the Independent Scientist Award from the National Institutes of Health in 1998 and the Honda Initiation Award in 2003. Professor Espy-Wilson has been appointed a Fellow of the Radcliffe Institute for Advanced Study for the academic year 2008–2009.

Current Post Doctoral Researchers

Xinhui Zhou

Post Doctoral Researcher

Email : zxinhui AT glue DOT umd DOT edu

Xinhui is a postdoctoral research associate working with both Professor Carol Y. Espy Wilson and Professor Shihab Shamma. His primary research interest is in speech signal processing, particularly in speech production and auditory signal processing, i.e. how human produces speech and how speech is processed in human auditory system.

Vahid Khanagha

Post Doctoral Researcher

Email : khanagha AT umd DOT edu

Vahid is a researcher at speech communication laboratory. His primary research interest is in speech signal processing, particularly in noise-robust speech analysis and also speech enhancement.

Current Graduate Students

Ganesh Sivaraman

Research Assistant

Email : ganesa90 AT umd DOT edu

Ganesh is interested in speech inverting.

Saurabh Sahu

Research Assistant

Email : ssahu89 AT umd DOT edu

Saurabh is a PhD student at SCL. He completed his bachelor's degree from Indian Institute of Technology, Kharagpur in 2011 in Electronics and Electrical Communication Engineering and joined UMD in Fall 2012. His research interest lies in Signal processing and Pattern recognition. Currently He is focusing on recognition of depressed speech.

Yi-Chun Ko

Research Assistant

Email : ginako AT umd DOT edu

Yi-Chun is a PhD student in the Department of Electrical & Computer Engineering. She earned her BS in Electrical Engineering from National Taiwan University in 2010. She started her PhD studies since Fall 2011, and joined the SCL in February 2013. Her research interests include signal processing and machine learning. She is now working on emotion recognition related research.

Yanbo Xu

Research Assistant

Email : yanbohsu AT umd DOT edu

Yanbo is a PhD student in ECE department. He earned his B.E.from Huazhong University of Science and Technology, China in 2010. He started his PhD studies since Fall 2010, and joined the SCL in Fall 2013. His research interests include speech enhancement, speech recognition, and speech forensics.


Post-Doctoral Researchers
Vikramjit Mitra (2011 ; currently at SRI Research Lab)
Om Deshmukh (2006 - 2007; currently at IBM India Research Lab)
Gongjun Li
Zhaoyan Zhang (2002 - 2004; currently Assistant Professor at the UCLA School of Medicine)
Suzanne Boyce (1994 - 1995; currently Assistant Professor at the University of Cincinnati)
Ph. D. Students
Name Graduated Title of Thesis Current Employment
Daniel Garcia-Romero


 “Robust Speaker Recognition Based on Latent

Variable Models”

Srikanth Vishnubhotla

Feb 2011

 “Segregation of Speech Signals in

Noisy Environments”

Vikram Mitra

Dec 2010

 “Articulatory Information for Robust

Speech Recognition”

Tarun Pruthi

Jan 2007

 “Analysis, Vocal-Tract Modeling, and

Automatic Detection of Vowel Nasalization”

Think A Move, Beachwood, OH
Om Deshmukh Jul 2006 “Synergy of Acoustic-Phonetics and Auditory Modeling Towards Robust Speech Recognition” IBM India Research
Amit Juneja Dec 2004 “Probabilistic landmark detection based on acoustic-phonetic information for automatic speech recognition” Think A Move
Nabil Bitar Fall 1997 “Acoustic modeling of speech based on phonetic features” GTE

M. S. (Thesis)

Name Graduated Title of Thesis Current Employment
Jingting Zhou ** 2011 "Automatic Speech CODEC Identification with Applications to Tampering Detection of Speech Recordings" Texas Instruments
Srikanth Vishnubhotla** Jan 2007

“Irregular Phonation Detection and Speaker ID”

PhD program at UMD

Sandeep Manocha **

Jul 2006

"Robust Voice Mining of Telephone Conversations" Microsoft
Thorvaldur Einarrson * Dec 2003 "Psychoacoustics based gain compensation for low listening levels"  

Ariel Salomon *

Dec 2000 "The Automatic Detection of Manner Landmarks using Simple Temporal Measures" PhD program at MIT

Michelle Delaney *

May 1998 "An Analysis of the Recognition Errors of a Phonetic Feature Based Speech Recognizer" Speechworks
Venkatesh Chari * May 1992 "Extraction of Formant Frequencies by Adaptive Enhancement of Fourier Spectra" Analog Devices

M.S. (Projects)

Name Duration Title of Project
Tarun Pruthi ** 2003 Automatic Classification of Nasal Consonants
Om Deskmush * 2001 A Direct Measure of Proportion of Periodic and Aperiodic Energy in Speech Signals
Amit JuneJa * 2001 Acoustic-Phonetic Approach to Speech Recognition Based on Event Detection and Linear Discriminant Analysis
Nandini Srinivasan * May 2000 Removal of Artificial Larynx Device Resonances through Inverse Filtering
Kun Xia * 2000 Refinement of Formant Tracker for Automatic Speech Recognition
Eric Craft * 2000 Automatic Classification of Baby Babble into Broad Classes
Arindam Mandel * 2000 Comparison of Knowledge-based Recognition with Human Performance Using Impoverished Speech
Bethany Broom * 2000 Combining Different Order LPC Spectra to obtain Reliable Pole Estimates for Automatic Formant Tracking
Heather Cundiff * 2000 Analysis of Acoustic and Articulatory Data for American English /r/
Kun Ma * May 1999 Improvement of Alaryngeal Speech through the Automatic Insertion of Prosodic Information
Pelin Demirel * May 1999 Improvement of Alaryngeal Speech through the Automatic Replacement of the Artificial Excitation Signal with a Normal Excitation Signal
Qian Zhang * May 1998 Recognition of Impoverished Speech
Zach McCaffrey * May 1998 Replacement of Artificial Voice Excitation Signal with Natural Excitation Signal using Cepstral Analysis
Deborah Schwartz * May 1996 Signal Processing Algorithms for Electrolaryngeal Speech Enhancement
Carla Valera * May 1997 Common Features of Devoiced Semivowels
Neeraj Deshmukh * May 1995 A Strategy for Acoustic Modeling to Increase Efficiency of HG
Kenneth Grimes * May 1992 Formant estimation of vowels using Critical-band Filtering
Jack McLaughlin * May 1992 Extraction of the glottal waveform using inverse filtering
Tamer Onat * May 1992 Vowel recognition using neural networks and phonetic features

Undergraduate Students in Research Programs

Name Duration Title of Research Project
Timothy Burke Fall 2006 Replacing STFT filter bank in MPO processing with an Auditory filter bank
Kunle Ogunsuyi Summer 2006 Speaker Recognition and Voice Mining
Bilal Raja Summer 2006 Recognition of Nasalized and Non-Nasalized Vowels
Chris Turnes Spring 2006 The dependence of the MPO model on the exact structure of the filterbank used in implementation (Spring)
Geetika Nagpal Fall 2005 The dependence of the MPO model on the exact structure of the filter bank used in implementation
Avinash Yentrapati Summer 2005 Articulatory synthesis of sustained speech.
Ayana George Summer 2005 Implementation of a Spectral Mean Subtraction Algorithm for Speech Enhancement
Sai Hei Yeung Summer 2005 MRI-based 3D Finite-element Analysis and Modeling of the Vocal Tract for American English /r/
Ryan Aminzadeh Summer 2005 Unsupervised Speaker Segmentation of two-speaker conversations
John Lin Fall 2004 & Spr 2005 Comparison of the acoustic properties of speech sound produced in upright vs. supine position
Shuo Chen Summer 2004 Acoustic Parameters for Identification of Nasalized Vowels
Thomas Plummer Summer 2004 The Investigation of Acoustical Features in Text-Independent Speaker Verification
Qin Zou Spring 2004 Compensation Algorithms to Minimize the Effect of Noise on Acoustic Speech Parameters
Jalaal Deeb Summer 2003 Speaker Adaptation in Text-Independent Speaker Verificaton
Paul Young Summer 2003 Creating Feature-Based Finite State Automata for Speech Recognition
First prize in the RITE (Research in Telecommunications Engineering) Program at the University of Maryland
Jawahar Singh Summer & Fall 2003 A Graded Method for Determining the Proportion of Periodic/Aperiodic Energy in Speech Signals
Shong Yin Summer 2002 Speaker Recognition Implemented via GMM and Vector Quantization
Jason Strohmeir Summer 2002 Multilayer Perceptron Neural Network for Speech Recognition
Kazuhito Niimi Spr 1994 Automatic classification of stop consonants
Stephanie Zierten Fall 1992 & Spr 1993 Automatic Detection of Place of Articulation in Stop Consonants
(Senior Honors Thesis)
Armen Balien Fall 1992 & Spr 1993 Automatic Detection of Acoustic Properties that Separate Adjacent Sounds with the Same Manner of Articulation
(Senior Honors Thesis)
Vinay Chandra Fall 1991 & Spr 1992 Automatic Discrimination of Strident and Nonstrident Fricatives
(Senior Honors Thesis)
Valerie Padilla Spring 1991 Detecting linguistic features for use in a speech recognition system
Charles Robinson Fall 1990 & Spr 1991 An Acoustic Study of the Influence of /r/ on different F3 trajectories (BS Thesis)
Shawn Williams Fall 1989 & Spr 1990 An Acoustic Study of the Feature Retroflex (BS Thesis)

* Boston University ; ** University of Maryland


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