Figure 1.

(A) Three types of audio datasets (PSG, Smartphone, Mixed), each divided into training, validation, and test sets. For example, the PSG audio dataset was divided into Train_PSG, Valid_PSG, Test_PSG. Model_PSG was trained using Train_PSG, Valid_PSG until performance saturation, and was then evaluated with Test_PSG. The same process was independently conducted for the Smartphone audio dataset and the mixed audio datasets (PSG+Smartphone), respectively. The numbers of subjects in each dataset were presented. (B) Pairs between trained models and test sets for cross-domain validation. Each trained model was evaluated on test sets from datasets not used for training the model.