Musical Instrument Spectral Envelope Sensitivity

While a number of studies have explored discrimination thresholds for changes to the spectral envelope, the question of how sensitivity varies as a function of centre frequency and bandwidth to musical instruments has yet to be addressed. In this paper we conducted a 2AFC experiment to observe the discrimination thresholds of the trumpet, clarinet and viola for 14 different modifications of centre frequency and bandwidth. The results indicate that perceptual sensitivity has an SNR upper bound of 20 dB, governed by the first few harmonics and sensitivity does not really improve when extending the bandwidth any higher. However, sensitivity was found to decrease if changes were made only to the higher harmonics and continued to decrease as the distorted bandwidth was widened. The results are analyzed and discussed with respect to two other spectral envelope discrimination studies in the literature as well as what is predicted from a psychoacoustic model.