Understanding Sound Levels and Why They Matter
Noise Overview: What Is a Decibel (dB)?
A decibel (dB) is a standardized unit used to measure sound level at a specific point. Unlike familiar linear measurements (such as inches or miles per hour), decibels are measured on a logarithmic scale, meaning changes in sound level are not perceived in equal steps.
In practical terms, this means:
- A small numerical increase in dB can represent a significant increase in perceived loudness
- An increase of 10 dB is generally perceived as twice as loud to the human ear
Understanding decibel levels provides critical context for evaluating comfort, safety, and performance in residential, commercial, and industrial environments.
Common Sound Levels (Typical dB Ranges)
The examples below illustrate how common sound sources compare on the decibel scale:
- 155 dB – Firearm discharge (extreme danger)
- 140 dB – Jet engine at close range / shotgun blast
- 130 dB – Riveting hammer (threshold of physical sensation)
- 120 dB – Propeller aircraft (threshold of pain)
- 110 dB – Rock drill / amplified live music
- 100 dB – Chainsaw / subway platform
- 90 dB – Lawn mower / heavy vehicle traffic (maximum recommended exposure for 8 hours)
- 80 dB – Print room / busy office equipment
- 70 dB – Noisy restaurant / urban traffic
- 60 dB – Normal conversation
- 40 dB – Quiet office or library
- 30 dB – Whisper
- 20 dB – Rustling leaves / insect noise
- 0 dB – Threshold of human hearing
Effects of Excessive Noise Exposure
Prolonged or repeated exposure to elevated sound levels can have serious and permanent consequences, including:
- Sustained exposure above 90 dB can result in irreversible hearing damage
- 120 dB may cause immediate pain and ringing in the ears (tinnitus)
- 140 dB and above can cause rapid and severe auditory nerve damage
Beyond hearing loss, excessive noise contributes to fatigue, stress, reduced concentration, and increased accident risk, particularly in occupational settings.
Why Noise Control Matters
Effective noise control is not simply about comfort—it is often a matter of safety, compliance, and performance.
Regulatory Compliance
Government agencies such as OSHA, along with state and local authorities, establish maximum allowable noise levels for workplaces and communities. Failure to comply can result in citations, fines, and operational restrictions.
Productivity and Safety
High noise levels interfere with communication, increase stress, and reduce situational awareness—factors that directly impact productivity and workplace safety.
Speech Clarity and Acoustics
In environments with excessive echo or reverberation—such as gyms, classrooms, offices, or auditoriums—speech intelligibility can be significantly degraded. Without proper acoustic control, even moderate noise levels can become disruptive.
Community and Environmental Impact
Uncontrolled environmental noise can lead to complaints, legal disputes, and declining property values. Effective noise control helps protect community relationships and long-term project viability.
Critical Listening Environments
Spaces such as recording studios, broadcast facilities, healthcare settings, and control rooms require exceptionally low background noise and controlled acoustics to ensure clarity, accuracy, and performance.
