The present study examines the question of a “natural” sonic feedback associated with keys of a numerical keyboard - in the context of use of an Automatic Teller Machine (ATM). “Natural” is defined here as an obvious sound feedback with regards to the action made by a user on a device. The aim is then to study how “naturalness” is related to the perceived usability and the perceived emotion of the sonic feedback before and after participants perform several tasks with the keyboard. Three levels of “naturalness” are defined: causal, iconic, and abstract. In addition, two levels of controlled usability of the system are used: a low level and a high one. Results show that preexperimental ratings of perceived “naturalness” and perceived usability were highly correlated. This relationship held after the participants interacted with the keyboard. “Naturalness” and emotional aspects were less dependant, revealing that “naturalness” and usability represent a special type of relation. However, results are affected by the level of controlled usability of the system. Indeed, the positive change at the high level of controlled usability for the iconic sounds (medium level of naturalness) obtained after the performance task failes at the low level of controlled usability.