I have a question about the confidence interval (CI) of the objective audio quality. Of course, CI should be a concept with the subjective quality scores. However, once we compute the objective score using one audio quality metric (such as PEAQ, PESQ, NMR, whatever), how much is this objective score believable with respect to the real quality, supposing we don?t know the real quality. For example, if the objective PEAQ score is -1.5, can we believe the magnitude of the real quality is [-2~-1]?
I tried to compute the CI by using the standard samples for PEAQ as following: the objective quality (ODG) is computed for each sample firstly, and then the difference (D) between ODG and subjective quality (SDG) is gotten, for all samples. I assume the difference D is approximately normally distributed, so the CI (e.g. 95%) of D can be computed according to the T-distribution table, standard deviation of D, and sample amount. For example, for PEAQ, the computed 95% CI is 0.16. Then, if the ODG of one sequence is computed by using PEAQ, can we think the subjective quality SDG should belong to the interval [ODG-0.16, ODG+0.16] with the probability 95%? Is this way to compute the CI of objective quality right?
I really appreciate any comment about this question, thank you so much.