A stereo system can fail for hundreds of reasons. About all you can do is make sure it is plugged in and all of the other cords are plugged in and that the speakers are working.If the stereo doesn't...
No, infrasound is the frequency of sound that is too low for humans to hear, below 20 hertz, but is used for communicating by elephants and other animals. Echolocation is normally ultrasound, the...