Ear

[long2019]

i see some people with a gadget in their ear is it amusic thing what are they called

[Prudie]

It's more likely a bluetooth device linked to their phones - although of course many listen to music on that.

[Buenchico]

A device such as this one
https://bit.ly/2mj9uev
is a Bluetooth headsets, which receives signals relayed from another Bluetooth devices, usually a mobile phone. (There are many other designs).

So the wearer can listen to the music stored on their phone without the need for any leads to the headset.

[TonyV]

could be blue tooth ear piece that will connect to a mobile phone.

http://vi.raptor.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=163499328510&category=80077&pm=1&ds=0&t=1562114322000&ver=0

[Vagus]

Or could be a hearing aid ;)

[Stephen_G]

If they look like these

Amazon.co.uk User Recommendation

Then they are for music, but you can also take and make calls through them, because they have a microphone built in. A lot of the audio manufacturers are making truly wireless earplugs, that connect via Bluetooth.

[Old_Geezer]

A finger.