What an audio ground isolator is used for
If 2 devices with protective contact plugs are connected via an audio cable, there is often sound interference. A compensating current that causes hum flows through the different ground potentials. Such devices can be, for example, computers and stereo systems. There is a similar effect if one of the devices is connected via an antenna connection, eg television, cable receiver, satellite receiver, car radio. In such cases, the audio ground isolator helps. The mass is galvanically isolated, so there is no longer any electrical connection between the devices. The audio signal is transmitted unaffected by this. This effectively removes background noise.