I am trying to find a device for which I don't know the name. Please help me find the name based on the following function functional description:
It should be an audio splitter (e.g. one input I, two outputs O1 and O2). The splitter outputs the audio to O1, unless a device (e.g. headphones) is plugged into O2; in that case, only O2 receives the output.
This is very similar to what many computers do: They have an audio line out in the back, and a headphone jack in the front. Normally, the audio is sent out the back, but if something is plugged into the headphone jack, the rear line out is muted and only the headphone jack receives audio.
A use case for the type of device that I am searching the name for, would be a computer that does not have this headphone jack. Simply adding such a device in between the audio output in the back and and the connected amp + speakers would add the functionally of a headphone jack.