1. What is the Sound Absorption Coefficient?

The sound absorption coefficient (α) is a measure of how much sound energy a material absorbs compared to how much it reflects. It ranges from 0 (perfect reflection) to 1 (perfect absorption).

2. How Does the Calculator Work?

The calculator uses the sound absorption coefficient formula:

Where:

• \( \alpha \) — Sound absorption coefficient (dimensionless)
• \( I_{abs} \) — Absorbed sound intensity (W/m²)
• \( I_{inc} \) — Incident sound intensity (W/m²)

Explanation: The coefficient represents the fraction of sound energy absorbed by the wall surface compared to the total incident energy.

3. Importance of Sound Absorption Calculation

Details: Understanding sound absorption is crucial for architectural acoustics, noise control, and designing spaces with optimal sound quality.

4. Using the Calculator

Tips: Enter both absorbed and incident sound intensities in W/m². Incident intensity must be greater than 0.

5. Frequently Asked Questions (FAQ)

Q1: What are typical α values for common materials?
A: Concrete (0.01-0.02), Carpet (0.3-0.5), Acoustic foam (0.6-0.9), Open windows (~1.0).

Q2: How is this different from sound transmission loss?
A: Absorption coefficient measures energy absorbed by a surface, while transmission loss measures energy passing through a material.

Q3: Why is α sometimes greater than 1?
A: Values >1 can occur in special test conditions where the effective absorption area is larger than the sample area.

Q4: How does frequency affect α?
A: Most materials have frequency-dependent absorption, with different α values at different frequencies.

Q5: What's the difference between Sabine and statistical absorption coefficients?
A: Sabine coefficients are measured in reverberation chambers, while statistical coefficients are derived from impedance tube measurements.