An illustration of the ALDEN framework, structured along two key axes: low-level signal disentanglement (vertical) and high-level semantic disentanglement (horizontal). ALDEN incorporates dual-level disentangled learning (scissors) and meta-learning (recycling) to improve generalization across different vocoders. By focusing on vocoder-agnostic features and synthetic-relevant cues, ALDEN enhances the model's generalization ability while minimizing sensitivity to irrelevant variations.