What are the words to express sobbing and crying sound?

Google doesn't help much.

What are the sounds (written in words) that people usually use to express their crying/sobbing emotions such as in chat, social network?

For example if I say, "I am sad [sobbing]", this is ok but I want to replace it with sound to express more emotion.

In my own language "sig sig" would be the sound for sobbing but I guess if I wrote "sig sig", English speaker friends wouldn't understand me.

For crying there is "Waa" or "Waah", which is usually to represent a babies cry (ie. a howling cry, not sobbing).

eg.

Waaaa! I dropped my phone and broke the screen!

Waa waa, cry me a river.

Boohoo

used to represent the sound of someone crying noisily.

For example, "Boohoo! I just lost my phone."

Blubber (informal)

cry noisily and uncontrollably; sob.

For example, "He was blubbering like a kid"

Bawl

to cry out loudly and unrestrainedly.

Caterwaul

to make a harsh cry (like a cat in heat).

Source: Oxford Dictionaries

Sniff sniff

This in fact is not a spoken word so much as a sound. It is the same sound made when someone is sniffing their nose as they are crying or trying to stop crying. The recovery sniffs is the sound you are mocking.

It is a sarcastic way to show someone you feel no pity for their situation.

Sob sob

A saying used when feeling unhappy or sad via text or email.

And then there are other ways to cry...

In English, the sound of crying is often given as "boo hoo." It's often used sarcastically as well to floccinaucinihilipilificate a reported problem (e.g. "You lost a quarter? Well boo hoo for you.") but it is the onomatopoeia in English for crying aloud.