1. What is the Decibel Distance Formula?

The decibel distance formula calculates how sound levels decrease with distance from a source. It's based on the inverse square law of sound propagation in free field conditions.

2. How Does the Calculator Work?

The calculator uses the decibel distance formula:

Where:

• \( L \) — Sound level at distance (dB)
• \( L_{ref} \) — Reference sound level (dB)
• \( r \) — Distance from source (meters)

Explanation: Sound intensity decreases with the square of the distance from the source. This formula converts that relationship to decibels.

3. Importance of Sound Level Calculation

Details: Understanding how sound levels change with distance is crucial for noise control, environmental assessments, and audio system design.

4. Using the Calculator

Tips: Enter the reference sound level in dB and distance in meters. The distance must be greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: Does this formula work in all environments?
A: No, this assumes free field conditions (no reflections or obstacles). Indoor environments typically show less attenuation.

Q2: How accurate is this calculation?
A: It's theoretically accurate for point sources in ideal conditions. Real-world factors like humidity, temperature, and obstacles affect results.

Q3: Why does sound decrease by 6 dB per distance doubling?
A: Because sound intensity follows an inverse square law - doubling distance reduces intensity to 1/4, which is -6 dB (10*log10(1/4)).

Q4: Can this be used for line sources?
A: No, line sources (like traffic on a road) follow different attenuation patterns (approximately 3 dB per distance doubling).

Q5: What about atmospheric absorption?
A: This formula doesn't account for frequency-dependent atmospheric absorption, which becomes significant over long distances (>100m) or at high frequencies.