big, deep, great
little, small
loud
quiet, silent, soft
choked, hoarse, muffled, stifled, strangled
choking, gasping, heaving, racking, shuddering
I couldn't hold back the heaving sobs.

dry

give, let out
break (down) into, burst into
My father broke down into sobs.

be racked by, be racked with, heave with, shake with
Her body was racked with sobs.

choke back, hold back, muffle, stifle
Choking back a sob, she ran to her father's chair.

hear

break from sb/sth, come from, escape sb/sth
A sob escaped her lips.

rise
A choked sob rose in his throat.

catch
A dry sob caught in her throat.

rack sth, shake sth
Deep racking sobs shook his whole body.

subside

story
You can't expect me to believe this sob story!

between sobs
‘I don't want to go!’ she said between sobs.

on a sob
Ellen choked on a sob before admitting the truth.

through sobs
He continued his story through stifled sobs.

with a sob
‘Why didn't you tell me?’ she asked with a sob.

sob from
a sob from George

a sob of despair, a sob of pain, a sob of relief
a great sob of despair

aloud
loudly
quietly, silently, softly
hysterically, uncontrollably, wildly
almost
He was pleading, almost sobbing, first silently and then aloud.

begin to, start to
He began to sob uncontrollably.

hear sb
I heard a child sob loudly.

into
She began sobbing into her pillow.

with
She was sobbing with pain and fear.

sob your heart out
begin sobing, start sobing
She started sobbing hysterically.