Speaker extraction and diarization are two crucial enabling techniques for speech applications.
Speaker extraction aims to extract a target speaker's voice from a multi-talk mixture, while speaker diarization demarcates speech segments by speaker, identifying `who spoke when'.
The previous studies have typically treated the two tasks independently. However, the two tasks share a similar objective, that is to disentangle the speakers in the spectral domain for the former but in the temporal domain for the latter.
It is logical to believe that the speaker turns obtained from speaker diarization can benefit speaker extraction, while the extracted speech offers more accurate speaker turns than the mixture speech.
In this paper, we propose a unified framework called Universal Speaker Extraction and Diarization (USED).
We extend the existing speaker extraction model to simultaneously extract the waveforms of all speakers.
We also employ a scenario-aware differentiated loss function to address the problem of sparsely overlapped speech in real-world conversations.
We show that the USED model significantly outperforms the baselines for both speaker extraction and diarization tasks, in both highly overlapped and sparsely overlapped scenarios.
