Acoustic Vector Sensor–Based Speaker Diarization Using Sound Intensity Analysis for Two-Speaker Dialogues

Speaker diarization is a key component of automatic speech recognition (ASR) systems, particularly in interview scenarios where speech segments must be assigned to individual speakers. This study presents a diarization algorithm based on sound intensity analysis using an Acoustic Vector Sensor (AVS). The algorithm determines the azimuth of each speaker, defines directional beams, and detects speaker activity by analyzing intensity distributions within each beam, enabling identification of both single and overlapping speech segments. A dedicated dataset of interview recordings involving five speakers was created for evaluation. Performance was assessed using the Diarization Error Rate (DER) metric and compared with the State-of-the-Art Pyannote.audio system. The proposed AVS-based method achieved a lower DER value (0.112) than Pyannote (0.213) without overlapping speech, and a DER equal to 0.187 with overlapping speech included, demonstrating improved diarization accuracy and better handling of overlapping speech. The algorithm does not require training, operates independently of speaker-specific features, and can be adapted to various acoustic conditions. The results confirm that AVS-based diarization provides a robust and interpretable alternative to neural approaches, particularly suitable for structured two-speaker dialogues such as physician–patient or interviewer–interviewee scenarios.