Subjective Speech Evaluation on Mobile Communication Networks
This study presents subjective speech evaluation on mobile communication networks, to determine speech quality level on mobile networks in Nigeria. The speech evaluation was based on subjective measurement methods using Mean Opinion Score (MOS). The subjective method was carried out in a quiet place at various times, with recommended sentences at different period respectively, five TECNO mobile equipments, with model number TECNO N3 and Andriod Version 2.3.5 were used, for a period of three Months. In addition, Network A, Network B and Network C, were considered in mobile communication networks in Nigeria. The male and female speech quality were examine from three different mobile networks, also comparison analysis were carried out from various networks to determine their speech quality, using various statistical tools such as Root Mean Square Error (RMSE) and Correlation Coefficient. In addition, various causes of drop calls and low (poor) speech quality levels were highlighted. It is observed that the total average RMSE value from the male speech quality obtained from the three networks considered is 0.601, while Correlation Coefficient value obtained between male and female speech quality were in variance. Also, Network A has higher (better) speech quality than Network B and Network C. In addition, speech distortions have lead to high number of drop calls in mobile communication networks in Nigeria.