Embedded systems such as mobile phones, tablets and GPS incorporate an increasing number of electronic functions that generate a decrease in battery life. The aim of this work is to propose new solutions for audio amplifiers for the headphone application because this application has a large impact on battery autonomy. To improve the efficiency of actual amplifiers, a behavioral model of this kind of amplifier has been developed and validated by practical measures. This model, fast, accurate and reconfigurable allows in few seconds to evaluate the efficiency, consumption and quality of sound reproduction in real conditions of operation. Through the use of this model coupled with an optimizing method based on two algorithms, several architectures of level detector were studied and compared allowing to define the best compromise. A new architecture is then proposed, simulated and optimized in a 0.25μm technology from ST Microelectronics to demonstrate the feasibility of the solution.