Systems and methods are described to enable a device of a user to automatically join an ongoing conference, where the device is not currently joined to the conference. A first audio signature is generated based on voices of users already in the conference, and a second audio signature is generated based on an audio signal captured by a microphone of the device associated with the first user when the device associated with the first user was not joined to the conference. The first audio signature and the second audio signature are compared, and in response to determining that first audio signature matches the second audio signature, the device associated with the first user is joined to the conference.