(of a telephone) produce a series of resonant or vibrating sounds to signal an incoming call.
All sound is vibrating, because sound is just air vibration, therefore any audio at all produces by a telephone fits this definition. I will die on this hill.
... Or perhaps the definition is just a bit outdated, only accounting for ringtones that sound like bells which used to be a popular choice. IMHO the definition should be updated to include any sound that alerts of an incoming call.