1. What is Magnitude Intensity Ratio?

Definition: The Magnitude Intensity Ratio (MIR) is a logarithmic measure comparing the intensity of a sound wave to a reference intensity.

Purpose: It provides a relative measure of sound intensity levels, commonly used in acoustics and seismology.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( MIR \) — Magnitude intensity ratio (dimensionless)
• \( I \) — Measured intensity (W/m²)
• \( I_0 \) — Reference intensity (typically 10⁻¹² W/m²)

Explanation: The ratio of intensities is calculated first, then the base-10 logarithm is applied to this ratio.

3. Importance of MIR Calculation

Details: MIR provides a way to compare sound intensities that can vary over many orders of magnitude using a more manageable scale.

4. Using the Calculator

Tips: Enter the measured intensity in W/m² and reference intensity (default 10⁻¹² W/m²). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical reference intensity?
A: The standard reference intensity is 10⁻¹² W/m², which is approximately the threshold of human hearing.

Q2: How is MIR related to decibels?
A: The decibel scale is similar but multiplies the MIR by 10 (dB = 10 × MIR).

Q3: What does a MIR of 0 mean?
A: A MIR of 0 means the measured intensity equals the reference intensity (I = I₀).

Q4: Can MIR be negative?
A: Yes, if the measured intensity is less than the reference intensity, MIR will be negative.

Q5: What's the practical range of MIR values?
A: Normal conversation might have MIR around 7 (10⁻⁵ W/m²), while painful sounds might reach MIR of 12 (1 W/m²).