Recent work from our lab illustrates amplitude envelope’s crucial role in both perceptual (Schutz, 2009) and cognitive (Schutz & Stefanucci, 2010) processing. Consequently, we surveyed the amplitude envelopes of sounds used in Music Perception, categorizing them as either flat (i.e., trapezoidal shape), percussive (aka “damped” or “decaying”), other, or undefined. Curiously, the undefined category represented the largest percentage of sounds observed, with 35% lacking definition of this important property (approximately 27% were percussive, 27% flat, and 11% other). This omission of relevant information was not indicative of general inattention to methodological detail. Studies using tones with undefined amplitude envelopes generally defined other properties such as spectral structure (85%), duration (80%), and even model of headphones/speakers (65%) at high rates. Consequently, this targeted omission is intriguing, and suggests amplitude envelope is an area ripe for future research.