Related Clues:

• Trumpeter's noise
• Whistle blast
• Driver's nonverbal 'hello'
• Tugboat noise
• Short blast of a whistle
• Train-whistle sound
• Whistle-blower's sound
• Tugboat's call
• Warning from a driver
• Loudspeaker's sound
• Whistle-blowing outcome?
• Play up to the max?
• Old-timey horn sound
• Do it on a flute
• Loud harsh noise