<p>Protection of the auditory system is effective when earplugs are capable of reducing the amplitude of sound waves reaching it. This effectiveness hinges on the composition, design, and correct insertion of the plugs. A precise fit ensures the formation of a tight seal in the ear canal, thereby preventing the entry of potentially harmful sound levels. In fact, the objective of this study is to assess the insertion depth using a 2D axisymmetric model of the human ear equipped with hearing protection. Indeed, an optimization method was performed to anticipate the insertion depth on the tympanic membrane behavior. This prediction aims to achieve optimal noise protection. By exploring the interplay between design, insertion depth, and effectiveness of hearing protection devices, this research contributes to refining strategies for personal noise protection, thereby fostering improved well-being in environments marked by persistent noise exposure. Indeed, the fined numerical model was validated against literature results.</p> Graphical Abstract <p></p>