A sound-based group discovery method is provided for collections of local devices. One of the devices initiates the discovery method by sending out a mating sound and, via a communications transceiver such as a short-range radio transceiver, a related mating signal. Any other device picking up both the mating sound and signal becomes at least a potential group member. In a preferred embodiment, the devices receiving both the mating sound and signal respond to the initiating device which thereupon determines an initial membership of the group and sends this to the other members. A sound connectivity check is then carried out to ensure each member can hear every other member.