"Um, excuse me..."

• ''Pardon me''
• Interrupter's word
• "If I may interrupt ..."
• Interrupting sound
• Polite cough sound
• "Attention, please!"
• Sound of a frog?
• "Pardon me..."

Wiktionary Word definitions in Wiktionary
interj. 1 (onomatopoeia) the sound of a quiet cough or of clearing one's throat 2 an exclamation or cough to get attention 3 an exclamation of disapproval or annoyance 4 an exclamation to indicate sarcasm n. A use of the interjection, ahem.

Wikipedia Word definitions in Wikipedia