Green’s Dictionary of Slang

squall n.2

also squawl
[weak use of SE]

(UK Und.) a voice.

[UK]New Canting Dict. n.p.: squawl a Voice; as, The cove has a bien Squawl; The Fellow has a good Voice.
[UK]Bailey Universal Etym. Eng. Dict. [as cit. 1725].
[UK]Mr Mathews’ Comic Annual 23: Hark! I hear another voice: I must look out for squalls – that’s not Jerry’s pipe.