Ususally refered to as (Pathetic Noise), <pathetic noise>, *pathetic noise* or Squeak, the pathetic noise is a high-pitched squeak noise produced by pushing air through pursed lips (not sucking). The air is pushed from the mouth with use of cheek muscles (not the lungs/diaphram).
The noise can take much practice and a long time to master, but once perfected it can become part of everyday speech quite easily.
Origionally a part of the Spacko
language, this has become a central point for many conversations in plain English too.
It can have many meanings (anger, jubilation, sorrow, etc), depending what context it is used in.