Interfaces play a crucial role in a device’s success or failure. Although visual aspects generally receive more attention, findings from sonic interaction design increasingly illustrate the importance of auditory aesthetics in creating desirable products. Here we show that small changes to the amplitude envelope (i.e., “sound shape”) of tones affect user preference. Specifically, participants are willing to pay 9% more for products using sounds with decaying-amplitude envelopes rather than abruptly ending envelopes that are common in many device sounds. These findings hold important implications for cost-effective changes that could potentially improve a product’s desirability and perceived value.