Evaluation on Quality of Voices Recorded from Testing into Different Mobile Phones and Telecom Networks

To provide a theoretical basis for examination of mobile phone's recording quality that is important for correct opinion to deliver in the forensic voiceprint identification of voice samples from the ubiquitous mobile phone calls. A quantitative standard was proposed for evaluation of the recorded samples that were obtained from the tested mobile phones and generation-various telecom networks. The standard, rooting on the basis of mainstream identification equipment, was analyzed into the quantity and digital values of formant in voiceprint spectrogram, fundamental frequency parameters, regional average spectrum and implemented voiceprint comparison test. The test results showed that certain differences existed with the recording quality under different conditions, having caused definite influence on voiceprint identification, yet at a non-essential extent. For voice identity authentication, the influence should be considered of recording quality differences on identification of the recorded samples from different mobile phones and telecom networks, therewith evaluated and overcome during identification.