Sound Sensor....
Sound sensors are generally a microphone used to detect the equivalent voltage of sound and return. The sound it receives can be navigated by a simple robot. Imagine a robot turning right to a pulpit, turning left for two palpitations. Complex robots may use the same microphone for voice recognition. Sound sensors are not as easy as light sensors because sound sensors generate a minimal voltage difference which should be amplified to produce a measurable change in voltage. Voice systems also use robots with voice commands. This is useful if the trainer has to handle other objects when training robots