| Author: | Chan, Chan-ping |
| Title: | Objective measure of speech intelligibility : a case study of public address system in Hong Kong Lantau Airport Railway Project |
| Degree: | M.Sc. |
| Year: | 1998 |
| Subject: | Public address systems -- China -- Hong Kong -- Case studies Speech processing systems -- Case studies Electro-acoustics -- Case studies Hong Kong Polytechnic University -- Dissertations |
| Department: | Multi-disciplinary Studies Department of Electronic Engineering |
| Pages: | vii, 64, [74] leaves : ill. ; 30 cm |
| Language: | English |
| Abstract: | Intelligibility is one of the most important elements to ensure that the public address announcement can be clearly heard by passengers in railway stations in which reverberation and noise are always the problems. There are subjective and objective measures to assess the intelligibility. The former suffers from human biases and is time consuming so that engineers are exploring the possibility of using the latter as the substitute. Among various objective measures, this report concentrates on Rapid Speech Transmission Index (RASTI) and Distance Measure of Log Area Ratios (DLAR). The former is currently the most popular measure for the public address system in the engineering field owing to the recognized position of its supporter, International Electrotechnical Commission (IEC) and availability of sophisticated equipment. The latter is selected for its similarity with the speech perception and superior quantization property of the LAR. This report builds the models of RASTI and DLAR and compares the simulation results of two models under various reverberation and noise conditions by a statistical analysis to probe their correlations and contrasts. Three important findings are obtained from the simulation. The first is the high correlation between RASTI and DLAR when only reverberation or noise is present. The second is that RASTI does not correlate with DLAR when both reverberation and noise are present. The last is that different words possess different DLAR values under test. Explanations for the findings are further explored. At the end, a site measurement is used to validate the theoretical results. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b14258419.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 13.21 MB | Adobe PDF | View/Open |
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