New chicken quarantined before adding to my flock

[Shaz1522]

Hi I got 4 bantams yesterday.i kept then in house over night while checking them over I noticed one makes this strange sound.like a quack or coughs it ok.ive put the others in there temp accommodation outside but left her inside for now.what do you think could it be because the lady had only just trimmed her beak as bottom was longer

 

[aart]

.like a quack or coughs it ok

A video would be most helpful, so we can hear the noise.

Some good tips about...
Biological/medical quarantine:
BYC Medical Quarantine Article