Dr Anton Ragni

BEng, MEng, PhD

School of Computer Science

Senior Lecturer in Speech and Language Technologies

Assessments Lead

Member of the Speech and Hearing (SpandH) research group

Anton Ragni profile photo
Profile picture of Anton Ragni profile photo
a.ragni@sheffield.ac.uk
Regent Court (DCS)

Full contact details

Dr Anton Ragni
School of Computer Science
Regent Court (DCS)
211 Portobello
Sheffield
S1 4DP
Profile

Dr Anton Ragni is a Senior Lecturer in Speech and Language Processing in the School of Computer Science at the University of Sheffield.

He graduated with BEng and MEng degrees in Information Technology from the University of Tartu, Estonia, in 2005 and 2007 respectively. He was awarded his PhD from the University of Cambridge in 2013.

From 2005 to 2008, he underwent graduate training at the Nordic Graduate School of Language Technology and from 2007 to 2008, he was an intern in the Speech Technology Group, Toshiba Research Europe Ltd, UK. From 2013 to 2018 and from 2018 to 2019, he was a Research Associate and Senior Research Associate, respectively, in Speech Processing at the University of Cambridge.

His current research interest focuses on machine learning approaches for speech and language processing.

Research interests

Dr Anton Ragni's research interests include:

  • Core automatic speech recognition
  • Efficient and expressive speech synthesis
  • Spoken Language Translation
  • Information Retrieval
  • Conversation Modelling
Publications

Books

  • Young S, Evermann G, Gales M, Hain T, Kershaw D, Xunying L, Moore G, Odell J, Ollason D, Povey D , Ragni A et al () The HTK Book (for HTK Version 3.5, documentation alpha version). Cambridge University Engineering Department: Cambridge University Engineering Department.

Journal articles

  • Mogridge R & Ragni A (2026) . Computer Speech & Language, 95.
  • Sun W, Tu Z & Ragni A (2024) . ICASSP 2024 - 2024 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 12667-12671.
  • Ma Y, land A, Ragni A, Sette BMD, Saitis C, Donahue C, Lin C, Plachouras C, Benetos E, Quinton E , Shatri E et al (2024) Foundation Models for Music: A Survey.. CoRR, abs/2408.14340.
  • Cross M & Ragni A (2024) What happens to diffusion model likelihood when your model is conditional?. Proceedings of Machine Learning Research, 255, 1-14.
  • Ragni A, Gales MJF, Rose O, Knill KM, Kastanos A, Li Q & Ness PM (2022) . IEEE/ACM Transactions on Audio, Speech, and Language Processing, 30, 1319-1329.
  • Wang Z & Ragni A (2021) Approximate Fixed-Points in Recurrent Neural Networks.
  • Jacobsen SA & Ragni A (2021) Continuous representations of intents for dialogue systems.
  • Chen X, Liu X, Wang Y, Ragni A, Wong JHM & Gales MJF (2019) . IEEE/ACM Transactions on Audio, Speech, and Language Processing, 27(9), 1444-1454.
  • Wu C, Gales MJF, Ragni A, Karanasou P & Sim KC (2018) . IEEE/ACM Transactions on Audio, Speech, and Language Processing, 26(2), 256-265.
  • Ragni A, Li Q, Gales MJF & Wang Y (2018) Confidence Estimation and Deletion Prediction Using Bidirectional Recurrent Neural Networks.. CoRR, abs/1810.13025.
  • Shi-Xiong Zhang , Ragni A & Gales MJF (2010) . IEEE Signal Processing Letters, 17(11), 945-948.
  • Flynn R & Ragni A () . Interspeech 2024, 2840-2844.

Book chapters

  • Ma Y, Yuan R, Li Y, Zhang G, Chen X, Yin H, Lin C, Benetos E, Ragni A, Gyenge N , Liu R et al (2023) ON THE EFFECTIVENESS OF SPEECH SELF-SUPERVISED LEARNING FOR MUSIC, Proceedings of the International Society for Music Information Retrieval Conference (pp. 457-465).
  • Nair S, Ragni A, Klejch O, Galu禳獺kov獺 P & Oard D (2020) , Lecture Notes in Computer Science (pp. 145-157). Springer International Publishing

Conference proceedings

  • Que S & Ragni A (2025) . Proceedings of Interspeech 2025 (pp 3778-3782). Rotterdam, The Netherlands, 17 August 2025 - 17 August 2025.
  • Leung W-Z, Cross M, Ragni A & Goetze S (2024) . Proceedings of Interspeech 2024 (pp 2494-2498). Kos island, Greece, 1 September 2024 - 1 September 2024.
  • Mogridge R, Close G, Sutherland R, Hain T, Barker J, Goetze S & Ragni A (2024) Non-Intrusive Speech Intelligibility Prediction for Hearing-Impaired Users Using Intermediate ASR Features and Human Memory Models.. ICASSP (pp 306-310)
  • Li Y, Yuan R, Zhang G, Ma Y, Chen X, Yin H, Xiao C, Lin C, Ragni A, Benetos E , Gyenge N et al (2024) MERT: ACOUSTIC MUSIC UNDERSTANDING MODEL WITH LARGE-SCALE SELF-SUPERVISED TRAINING. 12th International Conference on Learning Representations Iclr 2024
  • Sun W, Tu Z & Ragni A (2024) Energy-Based Models for Speech Synthesis.. ICASSP (pp 12667-12671)
  • Leung W-Z, Cross M, Ragni A & Goetze S (2024) Training Data Augmentation for Dysarthric Automatic Speech Recognition by Text-to-Dysarthric-Speech Synthesis.. INTERSPEECH
  • Flynn R & Ragni A (2024) Self-Train Before You Transcribe.. INTERSPEECH
  • Yuan R, Ma Y, Li Y, Zhang G, Chen X, Yin H, Zhuo L, Liu Y, Huang J, Tian Z , Deng B et al (2023) MARBLE: Music Audio Representation Benchmark for Universal Evaluation. Advances in Neural Information Processing Systems (NeurIPS 2023), Vol. 36. New Orleans, USA
  • Ma Y, Yuan R, Li Y, Zhang G, Lin C, Chen X, Ragni A, Yin H, Benetos E, Gyenge N , Liu R et al (2023) On the effectiveness of speech self-supervised learning for music.. ISMIR 2023: 24th International Society for Music Information Retrieval Conference proceedings (pp 457-465). Milan, Italy, 5 November 2023 - 5 November 2023.
  • Nomo Sudro P, Ragni A & Hain T (2023) . 2023 31st European Signal Processing Conference (EUSIPCO) Proceedings (pp 271-275). Helsinki, Finland, 4 September 2023 - 4 September 2023.
  • Flynn R & Ragni A (2023) . Proceedings of Interspeech 2023 (pp 1359-1363). Dublin, Ireland, 20 August 2024 - 20 August 2024.
  • Nicholls D, Knill K, Gales MJF, Ragni A & Ricketts P (2023) Speak & improve: L2 English speaking practice tool. Proceedings of Interspeech 2023 (pp 3669-3670). Dublin, Ireland, 20 August 2024 - 20 August 2024.
  • Mogridge R, Close G, Sutherland R, Goetze S & Ragni A (2023) Pre-Trained Intermediate ASR Features and Human Memory Simulation for Non-Intrusive Speech Intelligibility Prediction in the Clarity Prediction Challenge 2. he 4th Clarity Workshop on Machine Learning Challenges for Hearing Aids (Clarity-2023). https://claritychallenge.org/clarity2023-workshop/results.html, 19 August 2023 - 19 August 2023.
  • Flynn R & Ragni A (2023) Leveraging Cross-Utterance Context For ASR Decoding.. INTERSPEECH (pp 1359-1363)
  • Li Y, Yuan R, Zhang G, MA Y, Lin C, Chen X, Ragni A, Yin H, Hu Z, He H , Benetos E et al (2022) LV-49: MAP-Music2Vec: A Simple and Effective Baseline for Self-Supervised Music Audio Representation Learning. 23rd International Society for Music Information Retrieval Conference (ISMIR 2022). Bengaluru, India, 4 December 2022 - 4 December 2022.
  • Li Y, Zhang G, Yang B, Lin C, Ragni A, Wang S & Fu J (2022) HERB: Measuring hierarchical regional bias in pre-trained language models. Findings of the Association for Computational Linguistics: AACL-IJCNLP 2022 (pp 334-346). Online, 20 November 2022 - 20 November 2022.
  • Kastanos A, Ragni A & Gales MJF (2020) . ICASSP 2020 - 2020 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) (pp 6329-6333), 4 May 2020 - 8 May 2020.
  • Li Q, Ness PM, Ragni A & Gales MJF (2019) . ICASSP 2019 (pp 6755-6759). Brighton, UK, 12 May 2019 - 12 May 2019.
  • Ragni A, Li Q, Gales MJF & Wang Y (2019) . 2018 IEEE Spoken Language Technology Workshop (SLT) (pp 204-211). Athens, Greece, 18 December 2018 - 18 December 2018.
  • Oard DW, Carpuat M, Galusc獺kov獺 P, Barrow J, Nair S, Niu X, Shing H-C, Xu W, Zotkina E, McKeown KR , Muresan S et al (2019) Surprise Languages: Rapid-Response Cross-Language IR.. EVIA@NTCIR
  • Li Q, Ness P, Ragni A & Gales MJF (2019) Bi-directional Lattice Recurrent Neural Networks for Confidence Estimation.. ICASSP (pp 6755-6759)
  • Wang Y, Wong JHM, Gales MJF, Knill KM & Ragni A (2018) . 2018 IEEE Spoken Language Technology Workshop (SLT). Athens, Greece, 18 December 2018 - 21 December 2018.
  • Wang Y, Chen X, Gales MJF, Ragni A & Wong JHM (2018) . 2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP). Calgary, AB, Canada, 15 April 2018 - 20 April 2018.
  • Chen O, Ragni A, Gales M & Chen X (2018) . Proceedings of Interspeech 2018 (pp 3338-3342). Hyderabad, India, 2 September 2018 - 6 September 2018.
  • Knill K, Gales M, Kyriakopoulos K, Malinin A, Ragni A, Wang Y & Caines A (2018) . Interspeech 2018 (pp 1641-1645). Hyderabad, India, 2 September 2018 - 6 September 2018.
  • Ragni A & Gales M (2018) . Interspeech 2018 (pp 2217-2221). Hyderabad, India, 2 September 2018 - 6 September 2018.
  • Chen X, Liu X, Ragni A, Wang Y & Gales MJF (2017) . 2017 IEEE Automatic Speech Recognition and Understanding Workshop (ASRU). Okinawa, Japan, 16 December 2017 - 20 December 2017.
  • Malinin A, Knill K, Ragni A, Wang Y & Gales MJF (2017) . 7th ISCA Workshop on Speech and Language Technology in Education (SLaTE) (pp 144-149). Stockholm, Sweden, 25 August 2017 - 25 August 2017.
  • Chen X, Ragni A, Liu X & Gales MJF (2017) . Proceedings of Interspeech 2017 (pp 269-273). Stockholm, Sweden, 20 August 2017 - 24 August 2017.
  • Knill KM, Gales MJF, Kyriakopoulos K, Ragni A & Wang Y (2017) . Proceedings of Interspeech 2017 (pp 2774-2778). Stockholm, Sweden, 20 August 2017 - 24 August 2017.
  • Gales MJF, Knill KM & Ragni A (2017) . Speech and Computer : 19th International Conference, SPECOM 2017 (pp 3-19). Hatfield, UK, 12 September 2017 - 16 September 2017.
  • Malinin A, Ragni A, Knill K & Gales M (2017) . Proceedings of the 55th Annual Meeting of the Association for Computational Linguistics (Volume 2 : Short Papers). Vancouver, Canada, 30 July 2017 - 4 August 2017.
  • Ragni A, Wu C, Gales MJF, Vasilakes J & Knill KM (2017) . 2017 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) (pp 4830-4834). New Orleans, LA, USA, 5 March 2017 - 9 March 2017.
  • Ragni A, Saunders D, Zahemszky P, Vasilakes J, Gales MJF & Knill KM (2017) . 2017 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) (pp 5770-5774). New Orleans, LA, USA, 5 March 2017 - 9 March 2017.
  • Chen X, Ragni A, Vasilakes J, Liu X, Knill K & Gales MJF (2017) . 2017 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) (pp 5775-5779). New Orleans, LA, USA, 5 March 2017 - 9 March 2017.
  • Ragni A, Dakin E, Chen X, Gales MJF & Knill KM (2016) . Interspeech 2016. San Francisco, CA, USA, 8 September 2016 - 12 September 2016.
  • Yang J, Ragni A, Gales MJF & Knill KM (2016) . Interspeech 2016. San Francisco, CA, USA, 8 September 2016 - 12 September 2016.
  • Yang J, Zhang C, Ragni A, Gales MJF & Woodland PC (2016) . 2016 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP). Shanghai, China, 20 March 2016 - 25 March 2016.
  • van Dalen RC, Yang J, Wang H, Ragni A, Zhang C & Gales MJF (2016) . 2015 IEEE Workshop on Automatic Speech Recognition and Understanding (ASRU) (pp 160-166). Scottsdale, AZ, USA, 13 December 2015 - 13 December 2015.
  • Cui J, Kingsbury B, Ramabhadran B, Sethy A, Audhkhasi K, Cui X, Kislal E, Mangu L, Nussbaum-Thom M, Picheny M , T羹ske Z et al (2016) . 2015 IEEE Workshop on Automatic Speech Recognition and Understanding (ASRU) (pp 259-266). Scottsdale, AZ, USA, 13 December 2015 - 13 December 2015.
  • Mendels G, Cooper E, Soto V, Hirschberg J, Gales MJF, Knill KM, Ragni A & Wang H (2015) Improving speech recognition and keyword search for low resource languages using web data. INTERSPEECH 2015 : 16th Annual Conference of the International Speech Communication Association (pp 829-833). Dresden, Germany, 6 September 2015 - 10 September 2015.
  • Wang H, Ragni A, Gales MJF, Knill KM, Woodland PC & Zhang C (2015) Joint decoding of tandem and hybrid systems for improved keyword spotting on low resource languages. INTERSPEECH 2015 : 16th Annual Conference of the International Speech Communication Association (pp 3660-3664). Dresden, Germany, 6 September 2015 - 10 September 2015.
  • Gales MJF, Knill KM & Ragni A (2015) . 2015 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Vol. -(-) (pp 5186-5190). Brisbane, QLD, Australia, 19 April 2015 - 24 April 2015.
  • Ragni A, Gales MJF & Knill KM (2015) . 2015 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) (pp 4634-4638). Brisbane, QLD, Australia, 19 April 2015 - 24 April 2015.
  • Knill KM, Gales MJF, Ragni A & Rath SP (2014) Language independent and unsupervised acoustic models for speech recognition and keyword spotting. INTERSPEECH 2014 : 15th Annual Conference of the International Speech Communication Association. Singapore, 14 September 2014 - 18 September 2014.
  • Rath SP, Knill KM, Ragni A & Gales MJF (2014) Combining tandem and hybrid systems for improved speech recognition and keyword spotting on low resource languages. INTERSPEECH 2014 : 15th Annual Conference of the International Speech Communication Association (pp 835-839). Singapore, 14 September 2014 - 18 September 2014.
  • Ragni A, Knill KM, Rath SP & Gales MJF (2014) Data augmentation for low resource languages. INTERSPEECH 2014 : 15th Annual Conference of the International Speech Communication Association (pp 810-814). Singapore, 14 September 2014 - 18 September 2014.
  • Yoshioka T, Ragni A & Gales MJF (2014) . 2014 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) (pp 6344-6348). Florence, Italy, 4 May 2014 - 9 May 2014.
  • Gales MJF, Knill KM, Ragni A & Rath SP (2014) Speech recognition and keyword spotting for low-resource languages : Babel project research at CUED. Fourth International Workshop on Spoken Language Technologies for Under-Resourced Languages (SLTU-2014) (pp 16-23). St. Petersburg, Russia, 14 May 2014 - 14 May 2014.
  • van Dalen RC, Ragni A & Gales MJF (2013) . 2013 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) (pp 7619-7623). Vancouver, BC, Canada, 26 May 2013 - 26 May 2013.
  • Gales MJF, Ragni A, Zhang A & Dalen RCV (2012) Structured discriminative models for speech recognition. Symposium on Machine Learning in Speech and Language Processing (MLSLP). Portland, Oregon, USA, 14 September 2012 - 14 September 2012.
  • Roupakia Z, Ragni A & Gales MJF (2012) Rapid nonlinear speaker adaptation for large-vocabulary continuous speech recognition. INTERSPEECH 2012 : 13th Annual Conference of the International Speech Communication Association (pp 1784-1787). Portland, OR, USA, 9 September 2012 - 9 September 2012.
  • Ragni A & Gales MJF (2012) . 2012 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) (pp 4149-4152). Kyoto, Japan, 25 March 2012 - 25 March 2012.
  • Ragni A & Gales MJF (2012) . IEEE Workshop on Automatic Speech Recognition & Understanding (pp 119-124). Waikoloa, HI, USA, 11 December 2011 - 11 December 2011.
  • Ragni A & Gales MJF (2011) . 2011 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) (pp 4788-4791). Prague, Czech Republic, 22 May 2011 - 22 May 2011.
  • Gales MJF, Ragni A, AlDamarki H & Gautier C (2010) . 2009 IEEE Workshop on Automatic Speech Recognition & Understanding (pp 205-210). Merano, Italy, 13 December 2009 - 13 December 2009.
  • Ragni A (2007) Initial experiments with Estonian speech recognition. Proceedings of the 16th Nordic Conference of Computational Linguistics (NODALIDA 2007) (pp 249-252). Tartu, Estonia, 25 May 2007 - 25 May 2007.
  • Flynn R & Ragni A () . Interspeech 2024 (pp 217-221)
  • Mogridge R & Ragni A () . Interspeech 2024 (pp 2360-2364)
  • Roupakia Z, Ragni A & Gales MJF () . Interspeech 2012 (pp 1784-1787)

Preprints

  • Que S & Ragni A (2025) , arXiv.
  • Cross M & Ragni A (2024) , arXiv.
  • Ma Y, land A, Ragni A, Del Sette BM, Saitis C, Donahue C, Lin C, Plachouras C, Benetos E, Shatri E , Morreale F et al (2024) , arXiv.
  • Flynn R & Ragni A (2024) , arXiv.
  • Leung W-Z, Cross M, Ragni A & Goetze S (2024) , arXiv.
  • Mogridge R, Close G, Sutherland R, Hain T, Barker J, Goetze S & Ragni A (2024) , arXiv.
  • Sun W, Tu Z & Ragni A (2023) , arXiv.
  • Ma Y, Yuan R, Li Y, Zhang G, Chen X, Yin H, Lin C, Benetos E, Ragni A, Gyenge N , Liu R et al (2023) , arXiv.
  • Flynn R & Ragni A (2023) , arXiv.
  • Yuan R, Ma Y, Li Y, Zhang G, Chen X, Yin H, Zhuo L, Liu Y, Huang J, Tian Z , Deng B et al (2023) , arXiv.
  • Li Y, Zhang G, Yang B, Lin C, Wang S, Ragni A & Fu J (2022) , arXiv.
  • Wang Z & Ragni A (2021) , arXiv.
  • Jacobsen SA & Ragni A (2021) , arXiv.
  • Kastanos A, Ragni A & Gales M (2019) , arXiv.
  • Li Q, Ness P, Ragni A & Gales M (2018) , arXiv.
  • Ragni A, Li Q, Gales M & Wang Y (2018) , arXiv.
  • Wang Y, Chen X, Gales M, Ragni A & Wong J (2018) , arXiv.
  • Chen X, Liu X, Ragni A, Wang Y & Gales M (2017) , arXiv.
  • Chen X, Liu X, Ragni A, Wang Y & Gales MJF (2017) Future Word Contexts in Neural Network Language Models..
Grants
  • , EPSRC, 06/2021 - 11/2023, 瞿218,290, as PI
  • Automatic voice conversion for transforming professional adult voice actors to artificial child voice actors, Innovate UK, 01/2021 - 01/2023, 瞿173,605, as Co-PI
Professional activities and memberships

He is a member of IEEE, ISCA and a regular reviewer of major speech and machine learning journals and conferences.

Since 2016, he has been an Officer of ISCA Special Interest Group on Machine Learning in Speech and Language Processing. He received the Best Student Paper Award at the IEEE Workshop on Automatic Speech Recognition and Understanding for his paper Generative kernels for noise robust ASR co-authored with M. J. F. Gales in 2011.

Links

Speech and Hearing research group