The sound made by the phone network to indicate a ringing phone on the other end of the line. In other words, the sound you hear when you call someone else; and the sound someone else hears when they ...

The dialing technology in an analog telephone. Each digit has a physical button that transmits a different audio tone when depressed. Known as the dual-tone multifrequency (DTMF) system, the signal is ...

Over-the-counter products such as retinol, vitamin C creams, and niacinamide may improve an uneven skin tone. Other treatments include laser therapy and microdermabrasion. Although most cases of ...