to give attention with the ear; attend closely for the purpose of hearing; give ear.

to pay attention; heed; obey (often fol. by to )

Children don't always listen to their parents.

to wait attentively for a sound (usually fol. by for )

to listen for sounds of their return.

Informal . to convey a particular impression to the hearer; sound

The new recording doesn't listen as well as the old one.

Archaic . to give ear to; hear. ?

listen in,

to listen to a radio or television broadcast

Listen in tomorrow for the names of the lottery winners.

to overhear a conversation or communication, esp. by telephone; eavesdrop

Someone was listening in to his private calls.

noun

auditor , ear