Environmental Science

Permanent URI for this collection

http://etd.aau.edu.et/handle/123456789/35

Browse

Browsing Environmental Science by Subject "Aavc"

Now showing 1 - 1 of 1
  • No Thumbnail Available
    Item
    Audio-Visual Speech Recognition Using Lip Movement for Amharic Language
    (Addis Ababa University, 2017-10-05) Belete, Befkadu; Assabie, Yaregal (PhD)
    Automatic Speech Recognition (ASR) is a technology that allows a computer to identify the words that a person speaks into a microphone or telephone and convert it to a written text. In recent years, there have been many advances in automatic speech reading system with the inclusion of visual speech features to improve recognition accuracy under noisy conditions. By identifying lip movements and characterizing their associations with speech sounds, the performance of speech recognition systems can be improved, particularly when operating in noisy environments. The aim of this study is to design and develop automatic audio-visual Amharic speech recognition using lip reading. In this study, for face and mouth detection we use Viola-Jones object recognizer called haarcascade face detection and haarcascade mouth detection respectively, after the mouth detection ROI is extracted. Extracted ROI is used as an input for visual feature extraction. DWT is used for visual feature extraction and LDA is used to reduce visual feature vector. For audio feature extraction, we use MFCC. Integration of audio and visual features are done by decision fusion. As a result of this, we used three classifiers. The first one is the HMM classifier for audio only speech recognition, the second one is HMM classifier for visual only speech recognition and the third one is CHHM for audio- visual integration. In this study, we used our own data corpus called AAVC. We evaluated our audio-visual recognition system with two different sets: speaker dependent and speaker independent. We used those two evaluation sets for both phone (vowels) and isolated word recognition. For speaker dependent dataset, we found an overall word recognition of 60.42% for visual only, 65.31% for audio only and 70.1 % for audio-visual. We also found an overall vowels (phone) recognition of 71.45% for visual only, 76.34% for audio only and 83.92 % for audio-visual speech. For speaker independent dataset, we got an overall word recognition of 61% for visual only, 63.54% for audio only and 67.08% for audio-visual. The overall vowel (phone) recognition on the speaker independent dataset is 68.04% for visual only, 71.96% for audio only and 76.79 % for audio-visual speech.