  Deep generative models have emerged as a promising approach in the medical
image domain to address data scarcity. However, their use for sequential data
like respiratory sounds is less explored. In this work, we propose a
straightforward approach to augment imbalanced respiratory sound data using an
audio diffusion model as a conditional neural vocoder. We also demonstrate a
simple yet effective adversarial fine-tuning method to align features between
the synthetic and real respiratory sound samples to improve respiratory sound
classification performance. Our experimental results on the ICBHI dataset
demonstrate that the proposed adversarial fine-tuning is effective, while only
using the conventional augmentation method shows performance degradation.
Moreover, our method outperforms the baseline by 2.24% on the ICBHI Score and
improves the accuracy of the minority classes up to 26.58%. For the
supplementary material, we provide the code at
https://github.com/kaen2891/adversarial_fine-tuning_using_generated_respiratory_sound.
