The 35-Type station dial. Source: The Beatrice Company Bell Labs conducted exhaustive research to determine the best methods for tone dialing. They settled on a DTMF system for the control tones ...

The type of dial tone sound created by electronic voicemail systems to let users know that a message is waiting to be retrieved. The quick-sounding alert is heard when the receiver is picked up or ...

The wah-like master tone and beef-boosting bass contour controls allow users to dial in a wide range of tones with minimal effort. The Reverend Billy Corgan Signature Drop Z’s longer scale ...