This paper presents a finite-response coherence model of sonoluminescence in which bubble collapse acts as the trigger surface, while emission is governed by delayed coherence deformation and threshold release in a driven medium. A dimensionless coherence variable χ is introduced to represent the ability of the medium to sustain organised collective response under acoustic forcing. The equilibrium coherence state is derived from the competition between collapse-driving and intrinsic response timescales, while the realised coherence evolves through a finite-response relaxation law. This produces a non-Markovian, history-dependent system. The model reproduces near-collapse emission in the fast-response regime, while also predicting a distinct coherence-lag regime in which the emission peak shifts away from the geometric collapse minimum and tracks delayed coherence evolution instead. Degeneracy tests show that removing thermal contributions does not eliminate emission, while modifying damping and coherence thresholds changes the timing and structure of the flash. The framework therefore separates the trigger of sonoluminescence from its governing release mechanism and provides falsifiable predictions involving timing offsets, threshold behaviour, phase memory, and parameter-dependent emission delays.
Adam Sheldrick (Sun,) studied this question.