Related Clues:

• Pollution type
• Click or clack
• Headache intensifier
• Library no-no
• Mass confusion
• Static, e.g.
• Dissonance
• Cacoph-ony
• Urban pollutant
• Kipling's 'Gunga ___'
• A lot of noise
• It may be white
• Welter of sound
• Urban pollution
• Headache augmenter