| 2012 | LREC | Method for Collection of Acted Speech Using Various Situation Scripts. | Takahiro Miyajima, Hideaki Kikuchi, Katsuhiko Shirai, Shigeki Okawa |
| 2008 | ICASSP | Noisy speech recognition using temporal AM-FM combination. | Yotaro Kubo, Akira Kurematsu, Katsuhiko Shirai, Shigeki Okawa |
| 2008 | Interspeech | A comparative study on AM and FM features. | Yotaro Kubo, Shigeki Okawa, Akira Kurematsu, Katsuhiko Shirai |
| 2007 | Interspeech | A study on temporal features derived by analytic signal. | Yotaro Kubo, Shigeki Okawa, Akira Kurematsu, Katsuhiko Shirai |
| 2005 | Interspeech | Discrimination of speech, musical instruments and singing voices using the temporal patterns of sinusoidal segments in audio signals. | Toru Taniguchi, Akishige Adachi, Shigeki Okawa, Masaaki Honda, Katsuhiko Shirai |
| 2003 | Interspeech | Statistical estimation of phoneme's most stable point based on universal constraint. | Shigeki Okawa, Katsuhiko Shirai |
| 1999 | Interspeech | A recombination strategy for multi-band speech recognition based on mutual information criterion. | Shigeki Okawa, Takehiro Nakajima, Katsuhiko Shirai |
| 1998 | ICASSP | Multi-band speech recognition in noisy environments. | Shigeki Okawa, Enrico Bocchieri, Alexandros Potamianos |
| 1996 | Interspeech | Estimation of statistical phoneme center considering phonemic environments. | Shigeki Okawa, Katsuhiko Shirai |
| 1995 | Interspeech | Estimation of statistical phoneme center and its application to accurate phoneme modelling. | Shigeki Okawa, Katsuhiko Shirai |
| 1994 | ICASSP | Automatic training of phoneme dictionary based on mutual information criterion. | Shigeki Okawa, Tetsunori Kobayashi, Katsuhiko Shirai |
| 1994 | Interspeech | Phoneme recognition in various styles of utterance based on mutual information criterion. | Shigeki Okawa, Tetsunori Kobayashi, Katsuhiko Shirai |
| 1994 | Interspeech | Evaluation of phonetic feature recognition with a time-delay neural network. | Shigeki Okawa, Christoph Windheuser, Frdric Bimbot, Katsuhiko Shirai |
| 1993 | Interspeech | Word spotting in conversational speech based on phonemic unit likelihood by mutual information criterion. | Shigeki Okawa, Tetsunori Kobayashi, Katsuhiko Shirai |
| 1992 | Interspeech | Phoneme recognition in continuous speech based on mutual information considering phonemic duration and connectivity. | Katsuhiko Shirai, Shigeki Okawa, Tetsunori Kobayashi |