2001 Fiscal Year Final Research Report Summary
Research on physical measure and subjective evaluation method corresponding to speech transmission performance of rooms.
| Project/Area Number |
11650618
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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 |
Architectural environment/equipment
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| Research Institution | Kinki University |
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Principal Investigator |
ONAGA Hiroshi Kinki University, Faculty of Engineering, Associate Professor, 理工学部, 助教授 (20233570)
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| Project Period (FY) |
1999 – 2001
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| Keywords | speech transmission performance / articulation / intelligibility / speech transmission index / reverberation / speech rate / carrier phrase / word familiarlity |
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| Research Abstract |
The defect of STI was clarified by both theoretical examination and subjective experiment. The model calculation of STI on the change tendency showed that STI was determined by the degree of concentration of the energy on time axis, that contradict the widely accepted concept of importance of early energy for speech intelligibility. The word intelligibility test was carried out in the synthesized sound field with different energy concentration point, and it was shown that there is a case in which STI contradicts the intelligibility. The intelligibility test carried out for the single reflection sound field under background noise condition showed that the intelligibility score for positive and negative relative levels of single reflection took different values despite of the same STI values.
The subjective evaluation experiment was carried out using impulse response of the actual sound field, and the correspondence with various physical measures was examined. It was shown that the correlation between the subjective evaluation and each physical measure showed smaller value for large volume space. The evaluation of the speech transmission performance of the large volume space is future problem.
The effect of the speech rate on the intelligibility was examined. The intelligibility lowered with the increase of the speech rate in the reverberant fields, though the intelligibility is unrelated to the speech rate in background noise field. The lowering of the intelligibility by reverberation appeared clearly for elderly people than for young people.
The result of the examination on the intelligibility test method showed that it was effective to raise the sensitivity of the intelligibility test to add the carrier phrase and to use the fast speech rate in the reverberant field. It was shown that the use of low familiarity words might raise the sensitivity on the intelligibility test for both reverberant field and background noise field.
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