Abstract: To investigate the characteristics of the nonlinear acoustic response of a balanced armature transducer at high amplitude, a nonlinear dynamic equation is established, and the approximate solution for vibration displacement is derived using the small parameter method. Subsequently, assuming sound waves propagate in an ideal fluid medium and leveraging the characteristics of a linear time-invariant system, expressions for sound pressure and harmonic distortion are derived. The correlation of these acoustic responses with the nonlinear parameters of the transducer, vibration system resonance, and cavity resonance is discussed. The research results indicate that asymmetric nonlinear parameters induce displacement DC bias and even harmonic distortion. The nonlinearity of current transfer coefficient and stiffness mainly affects low-frequency distortion, while the nonlinearity of damping coefficient affects high-frequency distortion. When the excitation frequency or its harmonics approach the resonance frequency of either the vibration system or the acoustic cavity, the sound pressure level or harmonic distortion peaks.