Analytical modelling and simulations of acoustic interaction with avian egg

Sound reception inside avian eggs is crucial for embryonic development and hatching synchrony, yet, conventional techniques are unable to directly measure the complex transmission of sound within the egg. To address this, an analytical model is developed to predict the interaction between acoustic waves and avian eggs, providing comprehensive insights into the acoustic characteristics inside the eggshell. The model approximates the egg as a layered spherical system, consisting of an eggshell, albumen, and yolk, with the potential inclusion of an embedded sensor or embryonic structure. Governing equations for elastic and viscous media are formulated, and continuity conditions for displacement and stress are enforced at each interface. Comprehensive parametric simulations are conducted to examine the effects of geometric and mechanical properties on resonance frequencies and internal pressure amplification. The results demonstrate that the eggshell radius predominantly governs the acoustic response, whereas variations in shell thickness and material properties have secondary effects. Frequency-dependent pressure gains in the albumen and yolk reveal significant amplification near resonance. Additionally, the impact of sensor insertion is assessed to determine optimal dimensions for minimising measurement distortion.