COMMUNICATION QUALITY EVALUATION APPARATUS, COMMUNICATION QUALITY EVALUATION METHOD, AND PROGRAM
There is provided a communication quality evaluation apparatus including: an Equipment impairment factor Ie computing unit that computes an Equipment impairment factor Ie in a Rating factor R calculating expression of the E-model based on an assessment result obtained by assessing test speech sound by an subject based on DCR or ITU-R BS.1116 based on a subjective evaluation scale including both words indicating a difference in the test speech sound from reference speech sound and words indicating listening easiness of the test speech sound; and a Rating factor R computing unit that computes a Rating factor R of the E-model based on the computed Equipment impairment factor Ie.
1 . A communication quality evaluation apparatus comprising:
processing circuitry configured to
compute an Equipment impairment factor Ie in a Rating factor R calculating expression of the E-model based on an assessment result obtained by assessing test speech sound by an subject based on DCR or ITU-R BS.1116 based on a subjective evaluation scale including both words indicating a difference in the test speech sound from reference speech sound and words indicating listening easiness of the test speech sound; and
compute a Rating factor R of the E-model based on the computed Equipment impairment factor Ie.
2 . The communication quality evaluation apparatus according to claim 1 , the processing circuitry configured to compute an Equipment impairment factor Ie in a Rating factor R calculating expression of the E-model based on an estimation value of subjective assessment obtained by linearly converting a PESQ evaluation value of the test speech sound by using a regression expression obtained in advance for the assessment result and the PESQ evaluation value of the test speech sound.
3 . The communication quality evaluation apparatus according to claim 1 , wherein the subjective evaluation scale includes “5: no perceptible difference from reference speech sound”, “4: perceptible difference but audible”, “3: perceptible difference and slightly inaudible”, “2: perceptible difference and barely audible”, and “1: perceptible difference and almost inaudible”.
4 . The communication quality evaluation apparatus according to claim 1 , wherein the test speech sound includes speech sound in N×M×P conditions by P speakers, which is obtained by superimposing N stages of speech sound distortions and M stages of residual echoes in a stagewise manner when N, M, and P are integers of 1 or more, or output speech sound of a communication device.
5 . A communication quality evaluation method of steps executed by a communication quality evaluation apparatus, the method comprising:
an Equipment impairment factor Ie computing step of computing an Equipment impairment factor Ie in a Rating factor R calculating expression of the E-model based on an assessment result obtained by assessing test speech sound by an subject based on DCR or ITU-R BS.1116 based on a subjective evaluation scale including both words indicating a difference in the test speech sound from reference speech sound and words indicating listening easiness of the test speech sound; and
a Rating factor R computing step of computing a Rating factor R of the E-model based on the computed Equipment impairment factor Ie.
6 . The communication quality evaluation method according to claim 5 , wherein, in the Equipment impairment factor Ie computing step, an Equipment impairment factor Ie in a Rating factor R calculating expression of the E-model is computed based on an estimation value of subjective assessment obtained by linearly converting a PESQ evaluation value of the test speech sound by using a regression expression obtained in advance for the assessment result and the PESQ evaluation value of the test speech sound.
7 . A non-transitory computer readable medium storing a computer program for causing a computer to function as the communication quality evaluation apparatus according to claim 1 .