Nonlinearities in balanced armature transducers

Electromagnetic transducers using a balanced armature play an important role in hearing aids and in-ear headphones because they generate required sound output at high efficiency. This paper investigates the transfer behavior at high amplitudes and develops a lumped parameter model of this transducer that considers the nonlinearities caused by the geometry and material properties. This model is a basis for optimal transducer design, adjusting the armature in production and actively canceling the nonlinear distortion through nonlinear, adaptive control.