Possible Clues:

• Vibration from dreadful snore can start to echo
• The impressive effect of clarion calls
• Orator's vocal quality
• Ringing quality
• Quality of a deep, full and reverberating sound
• Centrally suppressing sonar cancels continuation of noise
• By the sound of it, it's about a boy with a broken cane
• Tesla debut: "Mechanical ___"
• Sympathetic vibration represented on a screen
• Run feature about a new church's echo