Abstract:
Ge‘ez is an ancient Semitic language of Ethiopia, which survives as the liturgical
language of the Ethiopian Orthodox Tewahedo Church (EOTC) and Eritrean
Orthodox Tewahedo Church. Beyond EOTC, several universities and colleges in
Ethiopia and abroad are offering courses in Ge‘ez language and literature. Ge‘ez has
kept not only EOTC liturgical manuscripts but also Ethiopian history, culture and
huge wisdom about medicine, astronomy, mathematics, philosophy and several
others. Ge‘ez language has unique pronunciation styles; knowing them is a key
requirement. Pronunciation of Ge‘ez word has significant implications for the
meaning of the word. It includes two broad pronunciation style categories, namely
major and minor. Those categories include several others, which can be characterized
by different features and become distinguishable with their unique characteristics.
Studying Ge‘ez pronunciation styles is a key part of the language and it is a
challenging task especially for beginners. The proposed system aimed to detect
mispronunciation of Ge‘ez words speech automatically. It includes data acquisition,
preprocessing, feature extraction, and classification. In audio signal processing, we
recorded both correctly pronounced and mispronounced words from EOTC scholars
and transformed the raw audio into MFCC and Mel spectrogram format. We proposed
two classifications: classification for mispronunciation detection and classification for
major pronunciation styles. Two models were built and tested using different feature
extraction techniques. The experimental result of end-to-end CNN model for
mispronunciation detection classification achieve 91% accuracy using MFCC and
97% using Mel spectrogram features. And for major Ge‘ez pronunciation styles
classification, 94% accuracy using MFCC and 97% accuracy using Mel spectrogram
were achieved. For mispronunciation detection, hybrid model or CNN with SVM
achieve an accuracy of 88.4% and 95% using MFCC and Mel spectrogram,
respectively. In terms of major Ge'ez pronunciation styles classification, the MFCC
achieve 92% accuracy and the Mel spectrogram achieve 94.5%.
Key word: Ge‘ez, Ge‘ez pronunciation styles, CNN, MFCC, Mel spectrogram