Possible Clues:

• Feline visit gets noisy reception
• Cry out about a poor act?
• Heckler's shout
• Mocking remark about lines at end of act being fluffed
• Jeer performance suffering setback in ring
• Ring dropped by local act juggling gets disapproving whistle
• Visit from Burmese perhaps showing disapproving expression
• Boo queen's visit?
• Bit of razzing
• Cry of disapproval