2005 Fiscal Year Final Research Report Summary
Development and Construct of Speech Privacy Protection System Using Masking Effect
| Project/Area Number |
15500138
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Sensitivity informatics/Soft computing
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| Research Institution | Yamaguchi University |
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Principal Investigator |
YAMAGUCHI Shizuma Yamaguchi University, Faculty of Engineering, Professor, 工学部, 教授 (80243624)
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| Co-Investigator(Kenkyū-buntansha) |
SAEKI Tetsuro Yamaguchi University, Faculty of Engineering, Research Associate, 工学部, 助手 (40249595)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Speech Privacy / Masking / Spectral Distance / Audibility / Compact / Portable / Light-weight |
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| Research Abstract |
Recently the importance of achieving speech privacy in open spaces has been emphasized. In this study, a system for achieving speech privacy using a masking noise was developed. We adopted a meaningless steady noise to mask speeches that has various power spectra, and closed headphones/throat microphones to deliver clear speech even in high noise environments.
1.The most effective index for achieving a satisfactory level of speech privacy is selected by evaluating various indices. From the results, spectral distance was selected as the best index for evaluating speech privacy.
2.The spectrum of speech differs between individuals, so using masking noise corresponding to individual voice spectra was effective in minimizing annoyance. From this viewpoint, a device was constructed to generate noise with the same spectrum form as a voice. Psychological experiments were conducted to consider the validity of the device constructed.
3.The above system had some problems : occasionally it radiated too much masking noise, and voice communication quality was slightly poor because the frequency characteristics of the throat microphones were not flat. To consider the effectiveness of reducing the noisiness and annoyance by using masking noise which takes background noise into account, and the effectiveness of improving audibility and listening score by correcting frequency characteristic of throat microphones, psychological experiments were conducted.
4.Psychological experiments were conducted to evaluate the developed compact/portable/light-wait system. The results confirmed the usefulness of the developed system.
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Research Products
(13 results)
