Acoustic system can be symbolized by a circuit composed of three basic elements as shown in the following figure:

Acoustic impedance:

unit: acoustic Ohm, dimension: kg m-4 s-1

• Assignments of variables

• Pression as an effort variable

• Volume velocity as a flow variable

• Convention for electro-acoustic analogy

• Effort-to-Voltage convention
  

Analogy-based analysis of a acoustic system

1. Simplification of a real system by using a symbolic circuit
   
2. Transform of the symbolic circuit to the corresponding analogue circuit
   Direct replacement of symbolic elements by analogue elements
   Holes and slits can be directly replaced by masses and resistances
   Closed volumes are replaced by compliances connected in one end with a common reference point
   
3. Analysis of the analogue circuit

Example using a electro-acoustic analogy:

Symbolic circuit (a)

Equivalent circuit (b)

More information

Related reading

Bruneau M., Manuel d acoustique fondamentale, Paris, Hermes, 1998.

Jouhaneau J., Notions elementaires d'acoustique - Electroacoustique, Paris, Tec&Doc, 1994.

Merhaut J., Theory of electroacoustics, McGraw-Hill, 1981.

Olson H. F., Acoustical engineering, D. van Nostrand Comp., Inc., 1957.

Rossi M., Electroacoustique, Presses Polytechniques Romandes, 1986.

Rufer L., La modelisation des microsystemes electromecaniques. in Mir, S. (Ed.), Conception des microsystemes sur silicium. Traite EGEM, Hermes Science Publications, pp. 101-128, 2002.

Senturia S. D., Microsystem Design, Kluwer Academic Publishers, 2001.

Tilmans H.A.C., "Equivalent circuit representation of electromechanical transducers: I. Lumped-parameter systems", J. Micromech. Microeng., vol. 6, pp. 157-176, 1996.

Tilmans H.A.C., "Equivalent circuit representation of electromechanical transducers: II. Distributed-parameter systems", J. Micromech. Microeng., vol. 7, pp. 285-309, 1997.