Meaning of 'sob your heart out'

[Pupil]

Test No. incompl/inter-44 "Speaking 1 (At the Theatre)", question 7

The leading lady is also absent from our stage and you can probably hear her ......... her heart out as I speak.

(a) sobbing
(b) soaking
(c) spitting
(d) calling

Test No. incompl/inter-44 "Speaking 1 (At the Theatre)", answer 7

The leading lady is also absent from our stage and you can probably hear her sobbing her heart out as I speak.

Correct answer: (a) sobbing

Hi!!! I don't get it!!! ..... you can probably hear her sobbing her heart out as I speak.
Answer, please
Many thanks
Pupil
_________________
the more we learn
the less we know

[Torsten]

Hi Pupil,

Here is the sentence you are referring to:

The leading lady is also absent from our stage and you can probably hear her sobbing her heart out as I speak.

The leading lady can not come out to the stage because she is crying too hard.

TOEIC listening, photographs: A hospital ward

[amna]

I can not get it, what is the meaning of sobbing her heart out, U said crying too hard, does it means crying alot,please explain it.

Thanks

[Torsten]

Yes, to sob your heart out means to cry very hard.

TOEIC listening, photographs: Chefs in a kitchen