| Presentation | 2007/12/13 A study of geometric dependency of cepstrum on vocal tract length Daisuke SAITO, Ryo MATSUURA, Satoshi ASAKAWA, Nobuaki MINEMATSU, Keikichi HIROSE, |
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| PDF Download Page | PDF download Page Link |
| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | In this paper, we theoretically and experimentally prove that the direction of cepstrum vectors strongly depends on vocal tract length and that this dependency is represented as rotation in the n dimensional cepstrum space. In speech recognition studies, vocal tract length normalization (VTLN) techniques are widely used to cancel age- and gender-differences. In VTLN, a frequency warping is often carried out and it can be implemented as a linear transformation in a cepstrum space ; c=Ac. However, the geometric properties of this transformation matrix A have not been well discussed. In this study, its properties are made clear using n dimensional geometry and it is shown that the matrix rotates any cepstrum vector similarly and apparently. Experimental results using resynthesized speech demonstrate that cepstrum vectors extracted from a speaker of 180[cm] in height and those from another speaker of 120[cm] in height are reasonably orthogonal. This result clarifies one of the reasons why children's speech is very difficult for conventional speech recognizers to deal with adequately. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | frequency warping / cepstrum / geometric property / rotation matrix / vocal tract length |
| Paper # | NLC2007-65,SP2007-128 |
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| Conference Information | |
| Committee | SP |
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| Conference Date | 2007/12/13(1days) |
| Place (in Japanese) | (See Japanese page) |
| Place (in English) | |
| Topics (in Japanese) | (See Japanese page) |
| Topics (in English) | |
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| Paper Information | |
| Registration To | Speech (SP) |
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| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | A study of geometric dependency of cepstrum on vocal tract length |
| Sub Title (in English) | |
| Keyword(1) | frequency warping |
| Keyword(2) | cepstrum |
| Keyword(3) | geometric property |
| Keyword(4) | rotation matrix |
| Keyword(5) | vocal tract length |
| 1st Author's Name | Daisuke SAITO |
| 1st Author's Affiliation | Graduate School of Frontier Sciences, The University of Tokyo() |
| 2nd Author's Name | Ryo MATSUURA |
| 2nd Author's Affiliation | Graduate School of Frontier Sciences, The University of Tokyo |
| 3rd Author's Name | Satoshi ASAKAWA |
| 3rd Author's Affiliation | Graduate School of Frontier Sciences, The University of Tokyo |
| 4th Author's Name | Nobuaki MINEMATSU |
| 4th Author's Affiliation | Graduate School of Frontier Sciences, The University of Tokyo |
| 5th Author's Name | Keikichi HIROSE |
| 5th Author's Affiliation | Graduate School of Information Science and Technology, The University of Tokyo |
| Date | 2007/12/13 |
| Paper # | NLC2007-65,SP2007-128 |
| Volume (vol) | vol.107 |
| Number (no) | 406 |
| Page | pp.pp.- |
| #Pages | 6 |
| Date of Issue | |