In human-computer interaction, low-key feedback is a type of output that takes a background role by being very subtle, sometimes nearly imperceptible.
Physical machines often provide rich low-key feedback as a byproduct of their design.
The downside of low-key feedback is that it can be too subtle to some users and it often cannot be self-describing to beginners.
In addition to the dashboard lights, the driver also perceives the sound and vibration of the engine.
Making the automobile completely silent might negatively impact the performance of the driver, as he must expend additional effort to stay informed about the operation of vehicle.