What is the proper name for this guinea pig sound please?

[tabelmabel]

Hiya - my piggies make a happy sound when we are petting them that sounds like a load of birds warbling inside them - is there a 'proper name' for this sound? Thanks

 

[twiams]

http://www.mgpr.org/newsite/GP_Info/Guinea Pig Sounds.htm this may help !

 

[tabelmabel]

Many thanks - it seems to be 'happy pig'!