Immittance was initially coined by H. W. Bode in 1945, and was first used to describe the electrical admittance or impedance of either a nodal or a mesh network.

In bioacoustics, immittance is typically used to help define the characteristics of noise reverberation within the middle ear and assist with differential diagnosis of middle-ear disease.

[1] Immittance is typically a complex number which can represent either or both the impedance and the admittance (ratio of voltage to current or vice versa in electrical circuits, or volume velocity to sound pressure or vice versa in acoustical systems) of a system.

[4] In electronics, an immittance Smith chart can be created by overlaying both the impedance and admittance grids, which is useful for cascading series-connected with parallel-connected electric circuits.

This allows for the visualization of changes in impedance or admittance in the system caused by components of either the series or parallel circuit.