Speech Intelligibility Evaluation for Mobile Phones

In the development process of modern telecommunication systems, such as mobile phones, it is common practice to use computer models to objectively evaluate the transmission quality of the system, instead of time-consuming perceptual listening tests. Such models have typically focused on the quality of the transmitted speech, while little or no attention has been provided to speech intelligibility. The present study investigated to what extent three state-of-the art speech intelligibility models could predict the intelligibility of noisy speech transmitted through mobile phones. Sentences from the Danish Dantale II speech material were mixed with three different kinds of background noise, transmitted through three different mobile phones, and recorded at the receiver via a local network simulator. The speech intelligibility of the transmitted sentences was assessed by six normal-hearing listeners and model predictions were compared to the perceptual data. Statistically significant differences between the intelligibility of the three phones were found in stationary speech-shaped noise. A good correspondence between the measured data and the predictions from one of the three models was found in all the considered conditions. Overall, the results suggest that speech intelligibility models inspired by auditory signal processing can be useful for the objective evaluation of speech transmission through mobile phones.