Here Z_b is the specific acoustic impedance of the cell boundary; R is the cell radius; c_b is the sound speed in the boundary material; and ρ_b is its density.

Electrical crosstalk must also be taken into account when evaluating the transfer function near a resonance frequency fₙ. Alongside the fitting of principal and subsidiary modes, the electrical amplitude Aₑₗₑₖ and phase difference Φₑₗₑₖ are included in the evaluation through the following additive term:

Original mathematical notation is preserved in the extracted image assets.