Dr. T. Nagarajan

 nagarajan PROFESSOR & HEAD OF THE DEPARTMENTDr. T. Nagarajan Ph.D

Email: nagarajant@ssn.edu.in

Extn: 217

Dr. T. Nagarajan earned his PhD degree from the Computer Science and Engineering department of IIT Madras in the year 2004. In his doctoral research, he was working on spoken language identification task. After his PhD, he joined TeNet group of IITM as a Senior-project-officer. During this period, he was working on a project, named, Multimodal Interface. Subsequently, he joined the National Institute of Scientific Research (INRS), Montreal, Canada, as a postdoctoral fellow and worked there for two years. During his postdoctoral research, he was focusing on Continuous speech recognition task, in which he specifically focused on discriminative training techniques for better classification.

After two years of postdoctoral research, he has joined SSN College of Engineering as a professor and he has been serving SSN since then. He has around 18 years of teaching experience. In addition to teaching, he has 7 years of pure-research experience both in India and abroad. Presently, he is a recognized supervisor of Anna University, Chennai, supervising four full-time Ph.D scholars, and has supervised two part-time PhD scholars, in the area of speech signal processing, speech synthesis and speaker recognition.

Dr. T. Nagarajan’s areas of research include speech signal processing, continuous speech recognition, statistical parametric speech synthesis, speaker verification/identification, spoken language identification, segmentation of speech into subword units, discriminative training techniques, and improved acoustic modeling techniques. He has published about 90 research papers in his area of research both in international journals and conference proceedings.

Project details:

  • Title: Speech Assistive Aids for Visually-Challenged People
    Funding Agency: Tamil Virtual Academy (TVA), Chennai
    Chief Investigator: Dr. T. Nagarajan
    Co-Investigator: Dr. P. Vijayalakshmi
    Status: Orally accepted
    Duration: 2017 – 2018
    Amount: Rs. 25 lakh
  • Title: Speech-Input Speech-Output Communication Aid (SISOCA) for Speakers with Cerebral Palsy
    Funding Agency: DST-TIDE
    Chief Investigator: Dr. P. Vijayalakshmi
    Co-Investigator: Dr. T. Nagarajan
    Status: Sanctioned
    Duration: 2017 – 2019
    Amount: Rs. 13.72 lakh
  • Title: HMM-based Text-to-Speech Synthesis System for Malaysian Tamil
    Funding Agency: Murasu Systems Sdn Bhd, Malaysia
    Chief Investigator: Dr. T. Nagarajan
    Co-Investigator: Dr. P. Vijayalakshmi
    Status: Ongoing
    Duration: 2016 – 2017
    Amount: Rs. 4 lakh
  • Title: Speech-Enabled Interactive Enquiry System in Tamil
    Funding Agency: Tamil Virtual Academy (TVA), Chennai
    Chief Investigator: Dr. T. Nagarajan
    Co-Investigators: Dr. P. Vijayalakshmi, Dr. B. Bharathi, Ms. S. Sasirekha
    Status: Ongoing
    Duration: 2016 – 2017
    Amount: Rs. 9.52 lakh
  • Title: Development of Text-to-Speech System in Indian Languages: High-Quality Text-to-Speech Synthesis and Small Footprint TTS Integrated with Disability Aids (A consortium project with IIT Madras as Team Leader)
    Funding Agency: Ministry of Electronics and Information Technology (MeitY), Government of India, New Delhi
    Chief Investigator at SSNCE: Dr. T. Nagarajan
    Co-Investigators at SSNCE: Dr. P. Vijayalakshmi and Dr. A. Shahina
    Status: Completed
    Duration: 2012 – 2017
    Amount: Rs.77 lakh
  • Title: An assessment and intelligibility modification system for dysarthric speakers
    Funding Agency: AICTE – RPS (A), New Delhi
    Investigators: Dr. P. Vijayalakshmi and Dr. T. Nagarajan
    Status: Completed
    Duration: 2010 – 2012
    Amount: Rs. 9 lakh
  • Title: Design of lab model of speech processor for cochlear implants
    Funding Agency: SSN Trust
    Investigators: Dr. P. Vijayalakshmi, Dr. T. Nagarajan & Dr. A. Shahina
    Status: Completed
    Duration: 2010 – 2012
    Amount: Rs. 0.8 lakh
  • Title: Anatomical vibration sensor speech corpus for speech applications in noisy environments.
    Funding Agency: SSN Trust
    Investigators: Dr. A. Shahina, Dr. T. Nagarajan & Dr. P. Vijayalakshmi
    Status: Completed
    Duration: 2010 – 2012
    Amount: Rs. 1.23 lakh

Publications:

Book chapters:

  1. P. Vijayalakshmi, T. Nagarajan, “Assessment and intelligibility modification for dysarthric speakers”, Voice Technologies for Reconstruction and Enhancement, De Gruyter Series in Speech Technology and Text Mining in Medicine and Healthcare (submitted).
  2. P. Vijayalakshmi, T. A. Mariya Celin, T. Nagarajan, “Selective pole modification-based technique for the analysis and detection of hypernasality”, Signal and Acoustic Modeling for Speech and Communication Disorders, De Gruyter Series in Speech Technology and Text Mining in Medicine and Healthcare (submitted).

Journal publications:

  1. G. Anushiya Rachel, P. Vijayalakshmi, T. Nagarajan, “Estimation of Glottal Closure Instants from Degraded Speech using a Phase-Difference-Based Algorithm”, Computer, Speech, and Language, Vol. 46, pp. 136 – 153, Nov. 2017.
  2. M. Dhanalakshmi, T. A. Mariya Celin, T. Nagarajan, P. Vijayalakshmi, “Speech-Input Speech-Output Communication for Dysarthric Speakers Using HMM-Based Speech Recognition and Adaptive Synthesis System”, Circuits, Systems and Signal Processing, May 2017, DOI 10.1007/s00034-017-0567-9.
  3. V. Sherlin Solomi, P. Vijayalakshmi, T. Nagarajan, “Exploiting Acoustic Similarities Between Tamil and Indian English in the Development of an HMM-based Bilingual Synthesizer”, IET Signal Processing, Vol. 11, Issue 3, pp. 332-340, May 2017.
  4. B. Ramani, M. P. Actlin Jeeva, P. Vijayalakshmi, T. Nagarajan, “A Multi-level GMM-Based Cross-Lingual Voice Conversion Using Language-Specific Mixture Weights for Polyglot Synthesis”, Circuits, Systems and Signal Processing, Vol. 35, pp. 1283-1311, Apr. 2016.
  5. M. P. Actlin Jeeva, T. Nagarajan, P. Vijayalakshmi, “DCT derived spectrum-based speech enhancement algorithm using temporal-domain multiband filtering”, IET Signal Processing, Vol. 10, Issue 8, pp. 965-980, Oct. 2016.
  6. G. Anushiya Rachel, V. Sherlin Solomi, K. Naveenkumar P. Vijayalakshmi and T. Nagarajan, “A small footprint context-independent HMM-based speech synthesizer for Tamil”, International Journal of Speech Technology, Vol. 18, Issue 3, pp. 405 – 418, Sep. 2015.
  7. N. Sripriya, T. Nagarajan, “Estimation of glottal closure instants considering the speech signal as a spectrum”, IET Electronic Letters, Vol. 51, Issue 8, pp. 649 – 651, Apr. 2015.
  8. B. Bharathi, T. Nagarajan, “Speaker verification using speaker-specific-text”, in WSEAS Transactions on Signal Processing, Vol. 10, pp. 320-330, July 2014.
  9. B. Bharathi, C. Arunkumar and T. Nagarajan, “Improving the performance of speaker and language identification task using unique characteristics of a class”, International Journal of Speech Technology, Vol. 16, Issue 1, pp. 115-124, 2012.
  10. P. Vijayalakshmi, T. Nagarajan and Preethi Mahadevan, “Improving speech intelligibility in cochlear implants using acoustic models”, WSEAS Transactions on Signal Processing, Vol. 7, Issue 4, pp. 103 – 116, Oct. 2011.
  11. P. Vijayalakshmi, T. Nagarajan and M. R. Reddy, “Assessment of articulatory and velopharyngeal sub-systems of dysarthric speech”, International Journal of BSCHS, special issue on Biosensors: Data acquisition, Processing and Control, Vol. 14, No. 2, pp 87 -94, Jun. 2009.
  12. G. Lakshmi Sarada, A. Lakshmi, T. Nagarajan and Hema A. Murthy, “Automatic transcription of continuous speech into syllable-like units for Indian languages”, SADHANA, Vol.34, part 2, pp. 221-233, April 2009.
  13. T. Nagarajan and Hema A. Murthy, “Language identification using acoustic log-likelihoods of syllable-like units”, Speech Communications, Elsevier publications, Vol.48, pp. 913-926, 2006.
  14. Douglas O’Shaughnessy, Wayne Wang, Willian Zhu, Vincent Barreaud, T. Nagarajan and R. Muralishankar, “Toward better automatic speech recognition”, Canadian Acoustics Journal, Vol. 33, No. 3, pp.48-49, 2005.
  15. T. Nagarajan and Hema A. Murthy, “Sub-band based Group delay segmentation of spontaneous speech into syllable-like units”, EURASIP Journal on Applied Signal Processing, Vol. 17, pp. 2612-2625, 2004.
  16. V. Kamakshi Prasad, T. Nagarajan and Hema A. Murthy, “Automatic segmentation of continuous speech using minimum phase group delay functions”, Speech Communications, Elsevier publications, Vol. 42, pp. 429-446, 2004.
  17. T. Nagarajan, V. Kamakshi Prasad and Hema A. Murthy, “The minimum phase signal derived from the root cepstrum”, IEE Electronic Letters, Vol. 39, No. 12, pp. 941-942, 2003.
  18. B. Ramani, M. P. Actlin Jeeva, T. Nagarajan, P. Vijayalakshmi, “A Multilingual to Polyglot speech synthesizer for Indian languages using multi-level GMM-based cross-lingual voice conversion”, Circuits, Systems and Signal Processing (second revision).
  19. G. Anushiya Rachel, P. Vijayalakshmi, T. Nagarajan, “Analysis of Algorithms to Estimate Glottal Closure Instants from Speech Signals”, IET Signal Processing (resubmitted after revision).
  20. G. Anushiya Rachel, N. Sripriya, P. Vijayalakshmi, T. Nagarajan, “Significance of Differenced EGG Signal as a Spectrum in Phase-Difference Computation for the Estimation of Glottal Closure Instants”, Circuits, Systems, and Signal Processing (resubmitted after revision).
  21. M. P. Actlin Jeeva, T. Nagarajan, P. Vijayalakshmi, “Noise-Adaptive Speech-Specific Dynamic Filter Structure-Based Sub-bands for Simultaneous Improvement of Quality and Intelligibility of Far-end Speech”, IEEE Transactions on Audio, Speech and Language Processing (submitted).
  22. K. Mrinalini, T. Nagarajan, P. Vijayalakshmi, “Pause-Induced Low-Resource Hybrid Machine Translation System”, IEEE Journal on Special Topics in Signal Processing (Special Issue: End-to-end systems) (submitted).

Conference publications:

  1. S. Johanan Joysingh, M. Nanmalar, G. Anushiya Rachel, V. Sherlin Solomi,                          P. Vijayalakshmi, T. Nagarajan, “Development of a Speech-Enabled Interactive Enquiry System in Tamil for Agriculture”, Tamil Internet Conference, Toronto, Canada, Aug. 2017 (accepted for publication).
  2. K. Mrinalini, G. Anushiya Rachel, T. Nagarajan, P. Vijayalakshmi, “Sentence-Medial Pause Identification for Tamil Synthesis System”, Tamil Internet Conference, Toronto, Canada, Aug. 2017 (accepted for publication).
  3. T. A. Mariya Celin, T. Nagarajan, P. Vijayalakshmi, “Dysarthric Speech Corpus in Tamil for Rehabilitation Research”, IEEE TENCON 2016, Singapore, Nov. 2016, pp. 2612 – 2615.
  4. V. Sherlin Solomi, G. Anushiya Rachel, P. Vijayalakshmi, T. Nagarajan, “Phone Mapping-based Mixed-language synthesizer for Tamil and Indian English”, Tamil Internet Conference, Gandhigram Rural Institute, Dindigul, Sep. 2016.
  5. M. P. Actlin Jeeva, T. Nagarajan, P. Vijayalakshmi, “Formant filters-based multiband speech enhancement algorithm for intelligibility improvement”, NCC, IIT Guwahati, Mar. 2016, pp. 243 – 248.
  6. M. P. Actlin Jeeva, P. Vijayalakshmi, T. Nagarajan, “Temporal-Domain Filtering Approach for Multiband Speech Enhancement”, International Conference on Microwave, Optical and Communication Engineering, IIT Bhubaneswar, Dec. 2015, pp. 385-388.
  7. G. Anushiya Rachel, P. Vijayalakshmi, T. Nagarajan, “Estimation of Glottal Closure Instants from Telephone Speech using a Group Delay-Based Approach that Considers Speech Signal as a Spectrum”, INTERSPEECH 2015, Dresden, Germany, Sep. 2015, pp. 1181-1185.
  8. I.  Janani Chellam, G. Anushiya Rachel, P. Vijayalakshmi, T.  Nagarajan, “Prosodic Modification of   Speech   to   Incorporate   Happy   and   Sad   Emotions”, IEEE  4th International Conference on Computation of Power, Energy, Information and Communication (ICCPEIC-2015), Apr. 2015, pp. 183 – 188.
  9. B. Ramani, M.P. Actlin Jeeva, P. Vijayalakshmi, T. Nagarajan, “Cross-Lingual Voice Conversion-Based Polyglot Speech Synthesizer for Indian Languages”, INTERSPEECH 2014, Singapore, Sep. 2014, pp. 775 – 779.
  10. Kishore Prahallad, Anandaswarup Vadapalli, Santosh Kesiraju, Hema A Murthy, Swaran Lata, T. Nagarajan, Mahadeva Prasanna, Hemant Patil, Anil Kumar Sao, Simon King, Alan W Black and Keiichi Tokuda, “The Blizzard Challenge 2014″, Singapore, Sep. 2014.
  11. V. Sherlin Solomi, M. S. Saranya, G. Anushiya Rachel, P. Vijayalakshmi, T. Nagarajan, “Performance Comparison of KLD and PoG Metrics for Finding the Acoustic Similarity Between Phonemes for the Development of a Polyglot Synthesizer”, IEEE TENCON 2014, Bangkok, Thailand, Oct. 2014, pp. 1 – 4.
  12. G. Anushiya Rachel, S. Sreenidhi, P. Vijayalakshmi, T. Nagarajan, “Incorporation of Happiness into Neutral Speech by Modifying Emotive-Keywords”, IEEE TENCON 2014, Bangkok, Thailand, Oct. 2014, pp. 1 – 6.
  13. T. Ramya, S. Lilly Christina, P. Vijayalakshmi, T. Nagarajan, “Analysis on MAP and MLLR-Based Speaker Adaptation Technique in Speech Recognition”, IEEE Int. Conf. on Circuit, Power and Computing Technologies (ICCPCT), 2014, pp. 1753 – 1758. (Best paper award).
  14. S. Sreenidhi, G. Anushiya Rachel, P. Vijayalakshmi, T. Nagarajan, “LP and TD-PSOLA-Based Incorporation of Happiness in Neutral Speech Using Time-Domain Parameters”, IEEE Int. Conf. on Circuit, Power and Computing Technologies (ICCPCT), 2014, pp. 1158 – 1162.
  15. Jaison Thomas and T. Nagarajan, “Development and evaluation of HMM based Malayalam and English polyglot synthesizer”, 3rd National conference on Advances in Computing Technology, Sriperumbudur, March 2014, pp. 1-3.
  16. K. Naveenkumar, T. Nagarajan, “Formant and Anti-Formant estimation from chirp group delay function”, 3rd National conference on Advances in Computing Technology, Sriperumbudur, March 2014, pp. 1-5.
  17. Sivaram LP, T. Nagarajan, “Estimation of Phrase Boundaries for Tamil Speech Synthesizer”, IEEE International Conference on Innovations in Engineering and Technology (ICIET’14), March 2014, pp. 1-5.
  18. Lilly Christina, P. Vijayalakshmi and T. Nagarajan, “Cross-lingual speaker adaptation in HMM-based speech synthesis” NCC 2014, IIT Kanpur, 2014, pp. 1 – 5.
  19. Anusha Prakash, M. Ramasubba Reddy, T. Nagarajan and Hema A Murthy “An Approach to Building Language-Independent Text-to-Speech Synthesis for Indian Languages”, NCC 2014, IIT Kanpur, 2014, pp. 1 – 5.
  20. H. A. Patil, T. B. Patel, N. J. Shah, H. B. Sailor, R. Krishnan, G. R. Kasthuri, T. Nagarajan, S. L. Christina, N. Kumar, V. Raghavendra, S. P. Kishore, S. R. M. Prasanna, N. Adiga, S. R. Singh, K. Anand, P. Kumar, B. C. Singh, S. L. Binil Kumar, T. G. Bhadran, T. Sajini, A. Saha, T. Basu, K. S. Rao, N. P. Narendra, A. K. Sao, R. Kumar, P. Talukdar, P. Acharyaa, S. Chandra, S. Lata, H. A. Murthy, “A syllable-based framework for unit selection synthesis in 13 Indian languages”,  Oriental COCOSDA/CASLRE 2013, Gurgaon, India, 2013, pp. 1 – 8.
  21. G. Anushiya Rachel, S. Lilly Christina, V. Sherlin Solomi, B. Ramani, P. Vijayalakshmi, T. Nagarajan, “Development and Analysis of Various Phone-Sized Unit-Based Speech Synthesizers”, Oriental COCOSDA/CASLRE 2013, Gurgaon, India, 2013, pp. 1 – 5.
  22. N. Sripriya, T. Nagarajan, “Estimation of instants of significant excitation using accumulated energy function of DCT”, Oriental COCOSDA/CASLRE 2013, Gurgaon, India, Nov 25-27, 2013, pp. 1 – 6.
  23. V. Sherlin Solomi, S. Lilly Christina, G. Anushiya Rachel, B. Ramani, P. Vijayalakshmi, T. Nagarajan, “Analysis on Acoustic Similarities between Tamil and English Phonemes using Product of Likelihood-Gaussians for an HMM-Based Mixed-Language Synthesizer”, Oriental COCOSDA/CASLRE 2013, Gurgaon, India, 2013, pp. 1 – 5.
  24. Ramani B, Actlin Jeeva M P, Vijayalakshmi P, Nagarajan T, “Voice Conversion-based Multilingual to Polyglot Speech Synthesizer for Indian Languages”, IEEE TENCON 2013, Xi’an, China, 2013, pp. 1 – 4.
  25. B. Bharathi and T. Nagarajan “GMM and i-vector based speaker verification using speaker-specific-text for short utterances”, IEEE TENCON 2013, at Xi’an, China, 22-25, Oct. 2013, pp. 1 – 4.
  26. B. Ramani, S. Lilly Christina, G. Anushiya Rachel, V. Sherlin Solomi, Mahesh Kumar Nandwana, Anusha Prakash, Aswin Shanmugam, Raghava Krishnan, S. Kishore Prahalad, K.Samudravijaya, P. Vijayalakshmi, T. Nagarajan and Hema Murthy, “A Common Attribute based Unified HTS Framework for Speech Synthesis in Indian Languages”, ISCA – SSW8, Barcelona, Spain , 2013, pp. 291 – 296.
  27. N. Sripriya, T. Nagarajan, “Pitch Estimation using Harmonic Product Spectrum derived from DCT”, IEEE TENCON 2013, China, Oct 22-25, 2013, pp. 1 – 4.
  28. M. Anbu Swarna Priyanka, V. Sherlin Solomi, P. Vijayalakshmi, T. Nagarajan, “Multiresolution Feature Extraction (MRFE) based speech recognition system”, International Conference on Recent Trends in Information Technology (ICRTIT), Chennai, July 2013, pp. 152-156.
  29. S. Magdalene Mahiba, S. Lilly Christina, P. Vijayalakshmi, T. Nagarajan, “Analysis of Cross-Gender Adaptation using MAP and MLLR in Speech Recognition System”, International Conference on Recent Trends in Information Technology (ICRTIT), Chennai, 25-27 July 2013, pp. 387-392.
  30. B. Ramani, V. Sherlin Solomi, G. Anushiya Rachel, S. Lilly Christina, P. Vijayalakshmi,                    T. Nagarajan, Hema A Murthy, “Development and Evaluation of Unit Selection and HMM-based Speech Synthesis for Tamil”, NCC 2013, Delhi, India, 2013, pp. 1 – 5.
  31. B. Bharathi and T. Nagarajan, “A two-level approach for speaker recognition using speaker-specific-text”, NCC 2013, IIT Delhi, Feb. 2013, pp. 1 – 4.
  32. M. Nanmalar, T. Nagarajan, “Multilingual Speech Recognition System for Indian Languages”, National Conference on Signal Processing, Communication Engineering (NCSCV 13), Anna University, Coimbatore, May 2013, pp. .
  33. Anusha, T. Nagarajan, “Prosody modeling for Tamil text-to-speech systems in FestVox framework”, National Conference on Signal Processing, Communication Engineering (NCSCV 13), Anna University, Coimbatore, May 2013.
  34. M. S. Saranya, T. Nagarajan,” Bilingual Text to Speech Synthesis Using HTS, National Trends in VLSI, Information and Communication, Dr. B. S. Abdur Rahman University, Chennai, Apr. 2013, pp. .
  35. K. Menaga, T. Nagarajan, “Development and Performance Analysis of Phoneme and CV-based Tamil Unit Selection Synthesis Systems”, ICCCC’13, Christian College of Engineering and Technology, Oddanchatram, Apr. 2013.
  36. M. Anbu Swarna Priyanka, V. Sherlin Solomi, P. Vijayalakshmi, T. Nagarajan, “Speech recognition system developed using Multiresolution Feature Extraction (MRFE) for sparse data”, National Conf. on Signal Processing, Communication and VLSI Design (NCSCV’13), 2013, pp. 302 – 306.
  37. S. Magdalene Mahiba, S. Lilly Christina, P. Vijayalakshmi, T. Nagarajan, “Speaker Adaptation Using MLLR and MAP Techniques in Speech Recognition System”, National Conf. on Signal Processing, Communication and VLSI Design (NCSCV’13), 2013, pp. 350 – 353.
  38. S. Johanan Joy Singh, G. Anushiya Rachel, P. Vijayalakshmi, T. Nagarajan, “Incorporating Emotions into Neutral Speech by Modifying Glottal Closure Instants”, National Conf. on Signal Processing, Communication and VLSI Design (NCSCV’13), 2013, pp. 339 – 343.
  39. M. Saranya, P. Vijayalakshmi and T. Nagarajan, “Improving the Intelligibility of Dysarthric Speech by Modifying System Parameters, Retaining Speaker’s Identity”, Proc. of the Second International Conference on Recent Trends in Information Technology, Apr. 2012, pp. 60 – 65.
  40. S. Lilly Christina, P. Vijayalakshmi and T. Nagarajan, “HMM Based Speech Recognition System for the Dysarthric Speech Evaluation of Articulatory Subsystem”, Second International Conference on Recent Tends in Information Technology, Apr. 2012, pp. 54 – 59.
  41. Anushiya Rachel Gladston, P. Vijayalakshmi and T. Nagarajan, “Improving Speech Intelligibility in Cochlear Implants Using Vocoder-Centric Acoustic Models”, Second International Conference on Recent Trends in Information Technology, Apr. 2012, pp. 66 – 71.
  42. P. Vijayalakshmi, B. Bharathi, T. Nagarajan, “Reducing the complexity of a triphone- based speech recognition system based on degree of coarticulation”, IEEE Technical symposium, IIT Kharagpur, Jan. 2011.
  43. B. Bharathi, P. Vijayalakshmi, T. Nagarajan “Speaker identification using utterances correspond to speaker-specific-text”, IEEE Technical symposium, IIT Khargpur, Jan. 2011.
  44. Saranya A, Sripriya N, T. Nagarajan, “Design of a VOCODER using instants of significant excitation”, International conference on Signal Processing, Communication, Computing and Network Technologies (ICSCCN-2011), July 2011, pp.742-746.
  45. T. Monica and T. Nagarajan, “Segmentation of speech signal into phonemes using two-level GMM-tokenization”, International Conference on Recent Trends in Information Technology, ICRTIT 2011, MIT, Chennai, Jun. 2011, pp. 843-847.
  46. Preethi M, Pavithra B, Shriranjani S, Vijayalakshmi P, and T. Nagarajan, “Cochlear Implant model using Mel-frequency cepstral coefficients”, Intl. conference on Implantable Auditory Prosthesis (CIAP) 2011, Jul., 2011, California.
  47. Preethi Mahadevan, T. Nagarajan, Pavithra B, S Shri Ranjani, Vijayalakshmi P, “Design of a lab model of a Digital Speech Processor for cochlear implant”, TENCON 2011, Indonesia, 2011, pp. 307 – 311
  48. P. Vijayalakshmi, Anu Abraham, B. Bharathi and T. Nagarajan, “Reducing the complexity of a triphone-based speech recognition system based on degree of coarticulation”, IEEE Techsym 2011, Jan. 2011, pp. 175 – 179.
  49. S. Harish, P. Vijayalakshmi and T. Nagarajan, “Significance of segmentation in Phoneme-based Tamil speech recognition system”, IEEE – ICECT, Apr. 2011, pp. 221 – 225.
  50. Anu Abraham, P. Vijayalakshmi and T. Nagarajan, “Pole focused linear prediction based spectrogram for coarticulation analysis”, IEEE Techsym 2010, IIT Kharagpur, Feb. 2010.
  51. C. Arun Kumar, B. Bharathi, and T. Nagarajan, “A Discriminative GMM Technique using Product of Likelihood Gaussians”, IEEE TENCON 2009, Singapore, Aug. 2009.
  52. P. Vijayalakshmi, P. Mukesh Kumar, Ra. V. Jayanthan and T. Nagarajan, “Cochlear Implant Models Based on Critical Band Filters”, IEEE TENCON 2009, Singapore, Aug. 2009.
  53. P. Vijayalakshmi, T. Nagarajan and Ra. V. Jayanthan, “Selective Pole Modification-Based Technique for the Analysis and Detection of Hypernasality”, IEEE TENCON 2009, Singapore, Aug. 2009.
  54. N. Sripriya, P. Vijayalakshmi, C. Arun Kumar and T. Nagarajan – “Estimation of instants of significant excitation from speech signal using temporal phase periodicity” – IEEE TENCON 2009, Nov. 2009, pp. 1 – 4.
  55. T. Nagarajan, and P. Vijayalakshmi, “Discriminative optimization of HMM Topology using product of likelihood – Gaussians”, National Conference on Communications, IIT Mumbai, 2008.
  56. T. Nagarajan and Douglas O’Shaughnessy, “Bias estimation and correction in a classifier using product of likelihood-Gaussians”, ICASSP – 2007, Hawaii, USA, pp. 1061-1064.
  57. T. Nagarajan and Douglas O’Shaughnessy, “Discriminative MLE training using a product of Gaussian likelihoods”, INTERSPEECH – 2006, Pittsburgh, USA, Sep. 2006, pp. 601-604.
  58. T. Nagarajan, P. Vijayalakshmi, and Douglas O’Shaughnessy, “Combining multiple-sized sub-word units in a speech recognition system using baseform selection”, INTERSPEECH – 2006, Pittsburgh, USA, Sep. 2006, pp. 1595 – 1597.
  59. Douglas O’Shaughnessy, T. Nagarajan, and Li Haozheng, “Better model and decoding methods for automatic speech recognition”, Acoustic Society of America – 151st Meeting, Jun. 2006.
  60. Douglas O’Shaughnessy, Wayne Wang, Willian Zhu, Vincent Barreaud, T. Nagarajan and R. Muralishankar, “Improving automatic speech recognition via better analysis and adaptation”, Acoustic Society of America – 150th Meeting, Vol.118, No. 3, Sep. 2005.
  61. T. Nagarajan and Douglas O’Shaughnessy, “Explicit segmentation of speech based on frequency-domain AR modeling”, INTERSPEECH – 2005, Lisbon, Portugal, Sep. 2005, pp. 653-656.
  62. G. L. Sarada, T. Nagarajan, Hema A. Murthy, “Multiple Frame Size and Multiple Frame Rate Feature Extraction for Continuous Speech Recognition”, SPCOM-2004, Bangalore, Dec. 2004, pp 592-595.
  63. N. Hemalatha, G. L. Sarada, T. Nagarajan, Hema A. Murthy, “Connected Digit Recognition using Unsupervised and Incremental HMMs”, NCC-2005, IIT Kharagpur, India, Jan 2005, pp. 296-299.
  64. M. Nageshwara Rao, S. Thomas, T. Nagarajan and H. A. Murthy, “Text-to-speech synthesis using syllable-like units”, NCC-2005, IIT Kharagpur, India, Jan 2005, pp 277-280.
  65. P. Sowjanya, K. Vijayalakshmi, G. Vijay Prakash, Kasi Rajan, M. S. Vidhya, T. Nagarajan, Srinivas Chakravarthy, N. S. Narayanaswamy and Hema A. Murthy, “Hand Writing Interface enabled Tamil Search Engine”, 11’th National Conference on Communications, IIT Kharagpur, Jan. 2005, pp 661-665.
  66. G. L. Sarada, T. Nagarajan, and Hema A. Murthy, “Automatic Transcription of continuous speech Using Unsupervised and Incremental Training”, INTERSPEECH – 2004, South Korea, Oct. 2004, pp. 405-408.
  67. T. Nagarajan, Hema A. Murthy and N. Hemalatha, “Automatic segmentation and labeling of continuous speech without bootstrapping”, EUSIPCO-2004, Vienna, Austria, Sep. 2004, pp. 561-564.
  68. T. Nagarajan and Hema A. Murthy, “Language identification using parallel syllable-like unit recognition”, ICASSP-2004, Montreal, Canada, May 2004, Vol. I, pp. 401-404.
  69. T. Nagarajan and Hema A. Murthy, “An approach to segmentation and labeling of continuous speech without bootstrapping”, Proc. NCC-2004, IISc, Bangalore, India, Jan. 2004, pp. 508-512.
  70. T. Nagarajan, Hema A. Murthy, and, Rajesh M. Hegde, “Segmentation of speech into syllable-like units”, Proc. EUROSPEECH-03, Geneva, Switzerland, Sep. 2003, pp. 2893-2896.
  71. T. Nagarajan and Hema A. Murthy, “Group delay based segmentation of spontaneous speech into syllable-like units”, ISCA and IEEE workshop on Spontaneous Speech Processing and Recognition, Tokyo, Japan, Apr. 2003, pp. 115-118.
  72. T. Nagarajan and Hema A. Murthy, “A pair-wise multiple codebook approach to implicit language identification”, Workshop on Spoken Language Processing, TIFR, India, Jan. 2003, pp.101-108.
  73. T. Nagarajan and Hema A. Murthy, “Language identification using spectral vector distribution across languages”, Proc. International Conference on Natural Language Processing, Dec. 2002, pp. 327-335.
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