Acoustic Impedance Calculator

Our acoustic impedance calculator can assist you in determining a material's particular acoustic impedance (z) as well as the intensity coefficients of transmission and reflection of a sound wave at the interface between two materials. Acoustic impedance has a wide range of applications, including soundproofing, ultrasonography, architectural acoustics, tympanometries, and aircraft noise management.

Continue reading to understand acoustic impedance, terms in the acoustic impedance equation, sound wave reflection and transmission, and the acoustic impedance of different materials.

What is Acoustic Impedance?

Will a sound from the same source behave the same in an air-filled room as it does underwater in a pool? Sound is a pressure wave that propagates across a medium, and the speed and strength of the wave are affected by the qualities of each material. The compressibility of a media (gas, liquid, or solid) determines how fast sound travels in that medium. Sound travels quicker in solids and liquids than in gases because solids and liquids are less compressible and have a larger modulus of elasticity.

A material's acoustic impedance (Z) determines how sound travels through it. It denotes the resistance of the medium to sound propagation, which influences the intensity of the sound. The greater the resistance to sound transmission, the higher the value of Z.

The wave's acoustic pressure to flow ratio determines the acoustic impedance (Z), which is unique to geometry and material. Similarly, the specific acoustic impedance (z) is a material property that connects the pressure of the wave to the velocity of the medium. The specific acoustic impedance formula for plane waves is given in terms of medium density (rho) and sound wave speed in that particular material (cc):


Let's compare the z of water and air at the same temperature, starting with our original query and utilizing the specific acoustic impedance equation:

  • Water has a z of 1.48 MRayl, with a density of 1000 kg/m3 and a sound speed of 1480 m/s.
  • Air has a z of 0.0004 MRayl and has a density of 1.225 kg/m3 and a speed of 343 m/s.

Even though sound travels 4.3 times faster in water than it does in air, the strength of the sound wave in air is 3700 times greater!

How do I use the Acoustic Impedance Calculator?

The acoustic impedance calculator can assist you in determining the particular acoustic impedance of certain material from a list or a bespoke material. The intensity reflection and transmission coefficients are also calculated using this tool:

To get the specific acoustic impedance of a material specified, use the following steps:

  • Step 1: Select the Acoustic impedance of the selected material from the find menu.
  • Step 2: Select the material for which you want to know the acoustic impedance from the Choose material list.
  • Step 3: The Specific acoustic impedance will be displayed by the calculator (z).

Using the acoustic impedance formula, determine the particular acoustic impedance of a custom material:

  • Step 1: Select Acoustic impedance of custom material from the Find menu.
  • Step 2: Fill in the density and sound speed of the material.
  • Step 3: The Specific acoustic impedance (z) value will be calculated by the calculator.

The intensity reflection (R) and transmission (T) coefficients are calculated as follows:

  • Step 1: Select Intensity reflection and transmission coef. from the Find menu.
  • Step 2: Make a list of the materials you'd want to study.
  • Step 3: The intensity coefficients R and T will be displayed by the calculator.

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FAQs on Acoustic Impedance Calculator

1. What does acoustic impedance mean?

The acoustic impedance is defined as the ratio of the particle velocity u in that wave to the (sinusoidal) acoustic pressure wave p.

2. What is a material's acoustic impedance?

The product of a material's density (ρ) and acoustic velocity (V) is its acoustic impedance (Z). Determining acoustic transmission and reflection at the interface between two materials with varying acoustic impedances

3. What is acoustic impedance and why is it important?

The acoustic impedance of an instrument for a given fingering is one of the most important aspects in determining the instrument's acoustic response in that fingering. It defines which notes may be played with that fingering, as well as their stability and whether or not they are in tune.

4. In geophysics, what is acoustic impedance?

The product of seismic velocity and density, acoustic impedance, is a fundamental physical property of rocks. Following proper initial processing, seismic traces are turned into pseudo reflection coefficient time series, which are subsequently inverted into acoustic impedance.

5. What is the definition of acoustic compliance?

A small volume's compressibility gives it acoustic compliance, whereas its inertia gives it acoustic instance. The acoustic impedance is the ratio of acoustic pressure to flow, and a duct has a particular impedance.