The decibel (dB) scale can be confusing. A 20 dB sound isn’t twice as loud as a 10 dB sound. This article explains how decibels work and why a 10 dB increase represents a significant jump in loudness.
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An audiogram charts a person’s hearing ability.
Decibels: Measuring Sound Intensity, Not Just Volume
Sound has two key characteristics: frequency (pitch) and amplitude (intensity or loudness). Frequency, measured in Hertz (Hz), describes how high or low a sound is. Amplitude, measured in decibels (dB), describes how loud a sound is.
The decibel scale is logarithmic, not linear. This means that for every 10 dB increase, the sound intensity increases tenfold. So, a 20 dB sound is ten times more intense than a 10 dB sound, not just twice as loud.
Why a 10 dB Increase is a Big Deal
Because the decibel scale is logarithmic, seemingly small increases in dB represent large changes in sound intensity.
- 10 dB increase: 10 times louder
- 20 dB increase: 100 times louder
- 30 dB increase: 1000 times louder
This exponential increase explains why a 20 dB sound is significantly louder than a 10 dB sound; it’s a hundredfold increase in intensity!
Real-World Examples of Decibel Levels
Understanding how decibels translate to real-world sounds can be helpful. Here are some common examples:
- 10 dB: Rustling leaves, a quiet whisper
- 20 dB: Ticking clock
- 60 dB: Normal conversation
- 85 dB: Heavy city traffic
- 90 dB: Lawn mower
- 120 dB: Siren, concert
- 140 dB: Fireworks
- 150+ dB: Firearms
Knowing when a sound is too loud can help protect your hearing.
Decibels and Hearing Loss
Exposure to loud noises, especially over prolonged periods, can damage hearing. Understanding the decibel scale helps assess the risk of noise-induced hearing loss. Sounds above 85 dB can cause damage over time, while sounds above 120 dB can cause immediate harm.
Protecting Your Hearing
To protect your hearing:
- Be aware of loud environments: Use earplugs or other hearing protection in noisy settings like concerts or when using power tools.
- Limit exposure time: Minimize the duration you spend in loud environments.
- Monitor headphone volume: Keep your headphone volume at a safe level.
- Get regular hearing checkups: Consult an audiologist for hearing tests and advice on hearing protection.
Understanding the Logarithmic Nature of Decibels is Crucial
The key takeaway is that the decibel scale is logarithmic, not linear. A 10 dB increase means a tenfold increase in sound intensity. This explains why a 20 dB sound is dramatically louder than a 10 dB sound – it’s 100 times more intense. Being aware of this difference can help you better understand sound levels and protect your hearing.
