Week 5: Noise Pollution

Overview

• Noise pollution involves excessive, unwanted, disruptive sounds that negatively affect health and environment.
• Characterized by sounds louder, more frequent, or different from ambient noise.

Characteristics of Noise

• Frequency:
  • Ranges from infrasonic (<80 Hz) to ultrasonic (>20,000 Hz).
  • Pitch perceived between 80 Hz-4,000 Hz; low frequencies travel further.
• Amplitude:
  • Loudness measured in decibels (dB).
  • Levels above 80 dB can damage hearing with prolonged exposure.
• Time Pattern:
  • Continuous noise is unvarying; intermittent noise has breaks.
  • Impulsive noise causes abrupt pressure changes.
• Other Characteristics:
  • Tonal quality, temporal characteristics, subjective perception.

Sources and Effects of Noise

Sources

• Industrial Activities:
  • Large machinery, power tools, boilers contribute to noise.
• Transportation:
  • Traffic density, vehicle speed, public vehicles impact noise levels.
• Construction:
  • Pile driving, excavation, and other activities generate noise.
• Urbanization:
  • Mixed land use, high population density lead to more noise.

Effects

• Human Health:
  • Hearing impairment, hypertension, sleep disorders, stress.
• Environmental:
  • Affects animal communication, foraging, breeding patterns.
• Indirect Effects:
  • Declining biodiversity, impacts on ecosystem services.

Measurements of Noise

• Sound Level Meters:
  • Measure amplitude and frequencies.
• Noise Mapping:
  • Uses GIS, models to map noise distribution.
• Standards:
  • WHO guidelines, national standards for noise levels.

Noise Control

• Source Control:
  • Quieter machinery, maintenance, soundproof enclosures.
• Transmission Path Control:
  • Planting vegetation, acoustic barriers.
• Receiver End Control:
  • Earplugs, sound insulation in buildings.

Managing Noise

Indoor Sound

• Soundproofing:
  • Insulation materials, seals reduce noise.
• Machinery:
  • Enclosures, maintenance reduce noise.
• Absorptive Treatments:
  • Soft furnishings absorb sound.

Outdoor Sound

• Noise Barriers:
  • Earth, concrete, vegetation barriers reduce noise.
• Urban Planning:
  • Zoning, green buffers to manage noise.

Malaysia Law on Noise

• Noise Regulations 2019:
  • Sets permissible noise levels for workplaces.
• Enforcement:
  • DOSH enforces; breaches can lead to fines.
• Related Laws:
  • Environmental Quality Act 1974, Town and Country Planning Act 1976.