Abstract: A process for assessing the signal quality of electromyographic (EMG) sensor signal data outputs based of a set of time domain and frequency domain signal performance metrics, including the magnitude of the baseline noise, line interference power spectra, and signal to baseline noise ratio parameters of the signal, whose calculated values are compared with a set of pre-defined acceptable values to determine whether or not the signal is of acceptable signal quality, and provide a pass/fail output. A graphic and text display output is provided to visually indicate the result. The visual display includes the presentation of the calculated parameter values of the baseline noise magnitude, line interference magnitude, and signal to baseline noise magnitude, using a combination of digital and analog indicators, each marked with the respective value of their pre-defined performance metric.