The purpose of this study was to determine if change in acoustic parameters of sustained vowel vocalization occurred in women with and without chronic knee pain when asked to rise from sitting to standing and if changes could be associated with occurrence of an emotion. Scherer's component process model of emotion and sequential check theory of emotion differentiation provided the framework for the study. Acoustic parameters evaluated were mean fundamental frequency, highest fundamental frequency, lowest fundamental frequency, range of fundamental frequency, jitter, shimmer, amplitude perturbation quotient, and three formant frequencies. Depression, anxiety and anger were measured and entered as interactions in mixed models to determine the influence of mood-related measures on acoustic parameters with non-pain and pain samples and with two levels of pain intensity. The sample consisted of 62 women 45 years of age or older: 32 women with knee pain of longer than 6 months' duration and 30 women with no musculoskeletal pain for comparison. Significant differences in range of fundamental frequency and jitter were observed between the non-pain and pain groups with stand tasks. Differences in shimmer, amplitude perturbation quotient and F2 were demonstrated between two pain intensity groups. Differences in range of F0 and jitter were associated with interactions of anxiety and anger.