Cat Talk

• Short meow - standard greeting.
• Multiple meows - excited greeting.
• Mid-pitch meow - plea for something.
• Drawn-out mrrroooow - a demand for something.
• Low pitch MRRRooooowww - a complaint
• High-pitch RRRROWW! - anger or pain.
• Chatter (rapid teeth-chattering jaw movements) - excitement, frustration (e.g. when prey is out of reach or escapes)
• Chirrup (a cross between a meow and a purr with rising inflection) - friendly greeting sound
• Purr - invites close contact or attention

source Wiki