Possible Clues:

• Now hear this
• Sound intensity unit
• A measure of noise disturbed bed lice
• Sound measure of the French bubbly, initially chilled, served up
• Last month starts with ringer short of volume
• Some noise for a month and bad-mouthing won't start
• Unit for measuring sound
• Noise unit declared current Big Ben perhaps must be curtailed
• Measure of sound
• Sound measure I'd associated with celeb in rehab