ETSI’s technical committee on Speech and multimedia Transmission Quality (TC STQ) has published testing methods to objectively evaluate the performance of super-wideband and full-band terminals for voice communications in the presence of background noise.
Background noise is a perennial issue for telecom terminal design. The higher the intended speech quality – such as wideband or super-wideband telephony – the more critical terminal optimization is.
To tackle this problem, ETSI TS 103 281 [PDF] provides testing methods and models to evaluate conversational services for teleconferences and audio-visual applications. It includes state-of-the-art codecs, typical communication packet loss and jitter conditions and recordings in handset, headset, hands-free and car hands-free mode.
To analyze the various parameters influencing speech quality, the new ETSI specification considers the speech quality, the background noise transmission quality and the overall quality. The objective models described in TS 103 281 are based on a huge subjective study conducted with American English, German, and Chinese (Mandarin) speakers. The prediction accuracy of the models is higher than most models currently on the market which is proven by the validation results also provided in the ETSI standard.
“The mobile industry was in demand of these testing methods.” says Hans Wilhelm Gierlich, chairman of the ETSI STQ technical committee.
The STQ committee continues work to develop methodologies, test arrangements and requirements for evaluating the performance of wearable devices for speech communication.
The group is also working on a specification aimed at improving listening quality for people with impaired hearing. The specification will define requirements and measurement methods to assess the impact of different transmission impairments on intelligibility as well as a model to assess speech intelligibility objectively. It is expected to be published later this year.