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Acoustic Impedance Calculator.

Calculate specific acoustic impedance from density and sound speed.

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impedance: 1,480,000

impedance

1,480,000.000000

Use Cases

Ultrasound and medical imaging

Acoustic impedance matching between tissues affects image quality. This calculator helps estimate impedance for different biological materials.

Example: For muscle (density 1070 kg/m³, sound speed 1580 m/s), Z ≈ 1.69 MRayl.

Acoustic engineering and material selection

Engineers use impedance values to design soundproofing, transducers, and acoustic sensors. This tool simplifies the calculation for various materials.

Example: For steel (density 7850 kg/m³, sound speed 5900 m/s), Z ≈ 46.3 MRayl.

Frequently Asked Questions

What is specific acoustic impedance?
Specific acoustic impedance (Z) is the product of the medium's density (ρ) and the speed of sound (c) in that medium. It represents how much acoustic pressure is generated by a given particle velocity. The unit is Rayl (kg/m²·s).
How do I use this calculator?
Enter the medium density in kg/m³ and the sound speed in m/s. The calculator multiplies these values to give the specific acoustic impedance in Rayl. For example, for air (density 1.225 kg/m³, sound speed 343 m/s), the impedance is about 420 Rayl.
Why is acoustic impedance important?
Acoustic impedance is crucial for understanding sound reflection and transmission at boundaries between different media. It's used in ultrasound imaging, sonar, and architectural acoustics to predict how much sound will be reflected or absorbed.

Tips & Common Mistakes

Tips

  • Ensure density is in kg/m³ and sound speed in m/s to get impedance in Rayl (kg/m²·s).
  • For gases, density varies with temperature and pressure; use values at your specific conditions.
  • For solids, sound speed can differ for longitudinal and shear waves; use the appropriate speed for your application.
  • Remember that impedance is a specific property; for total acoustic impedance, multiply by area.

Common Mistakes to Avoid

  • Using density in g/cm³ instead of kg/m³ (multiply by 1000 to convert).
  • Using sound speed in km/s instead of m/s (multiply by 1000).
  • Confusing specific acoustic impedance with acoustic impedance (which includes area).

Last updated: August 13, 2026