Phone circuits are busy pointer. A busy signal is a signal that indicates that someone is trying to call a phone number but could not be contacted because the phone if it is not involved, or because the circuits are busy, calls are impossible to solve. On many phones, busy signals take the form of a distinctive tone, but a busy signal can also be visual, as in the case yanga phone designed for users of deafness or hearing impairment. Many people are familiar with a busy signal sounds, because significantly different from the dial tone, a tone that indicates that the phone line is open and ready to be called. In most cases, only a busy signal indicates that the person you are calling is a call. A busy signal will also sound when the phone is turned off. In this case, the signal indicates that there are no technical obstacles to placing the call, but calls can not be completed because the phone is in use. In some cases, you can ask the operator to enter, if you call in an emergency, in t...