Meaning of 'TO LISTEN TO' and 'TO LISTEN IN'

[cowboy]

Hello. my dear friends. I am in a maze.
Today I saw the expression:
TO LISTEN OUT FOR PEOPLE

Test No. incompl/inter-42 "Keeping it Quiet", question 8

The rescuers tried desperately to listen out for people trapped in the wreckage but sadly the cries of those trapped were ..........

(a) unhearing
(b) auditory
(c) audited
(d) inaudible

Test No. incompl/inter-42 "Keeping it Quiet", answer 8

The rescuers tried desperately to listen out for people trapped in the wreckage but sadly the cries of those trapped were inaudible.

Correct answer: (d) inaudible

I don't understand it. I know only expressions:
TO LISTEN TO and TO LISTEN IN.
Tell me , please about it.
Many thanks in advance.
cowboy

[Alan]

Hi Cowboy,

Thanks for contributing to the forum. The expression 'listen out for' means listen very carefully so that you can hear someone or something you are expecting. Let me give you an example. Imagine you are expecting the postman to bring you a parcel one morning and you don't want to miss him. You know approximately what time the postman usually comes and so at that time you are very attentive and wait to hear him ring the bell and you listen out for him. Again someone has told you that an actor has a particular way of pronouncing a certain letter and says: Next time you hear that actor on television listen out for the way he pronounces the letter 'r'.

Hope this helps

Best wishes

Alan
_________________
English as a Second Language
You can read my ESL story Relative Pronoun

[cowboy]

Hello Alan. Your examples helped me to understand this expression.
Many thanks.
Cowboy

[Bob]

Hum...interesting. You are always excellent teacher for us, Alan.