Speaker Change Detection Metrics Using Interval-Overlap Evaluation

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Solution Overview

Problem

Conventional speaker change detection models suffer from performance degradations due to subjective variations in annotated training data, making it difficult to accurately identify speaker transition points in multi-speaker conversations.

Innovation Solution

A method and system for evaluating speaker change detection using a sequence transduction model that generates predicted speaker change tokens, with a training process that determines precision and recall metrics based on overlap with ground-truth intervals, allowing for improved model training and performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional speaker change detection models use annotated training data, then the model can be trained to identify speaker transitions, but the performance degrades due to subjective variations in annotation

Engineering Contradiction:
Improvespeaker transition point identification accuracyVSAvoidmodel performance consistency
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces an evaluation metric system that acts as an intermediary between the model predictions and the ground truth annotations. Instead of directly comparing predicted transition points with subjective annotations, the system uses precision and recall metrics that evaluate predictions based on their temporal proximity to annotated intervals. This intermediary evaluation framework reduces the impact of annotation subjectivity by allowing predictions within a tolerance window to be considered correct, thereby improving model performance consistency while maintaining the ability to identify speaker transitions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the model requires exact time point matching for speaker transitions, then measurement precision improves, but reliability decreases due to annotation subjectivity

Engineering Contradiction:
Improvespeaker transition time point accuracyVSAvoidperformance degradation from annotation variations
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent changes the evaluation parameter from exact time point matching to temporal interval overlap measurement. Instead of requiring predictions to match annotated transition points exactly, the system evaluates predictions based on whether they fall within or overlap with annotated time intervals. This parameter change allows the model to achieve both high measurement precision (by evaluating temporal accuracy) and high reliability (by tolerating reasonable variations in annotation timing), directly resolving the contradiction between precision and reliability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS12518762B2Evaluation-based speaker change detection evaluation metrics
Publication Date: 2026.01.06 GOOGLE LLC
  • US12518762B2 patent drawing
  • US12518762B2 patent drawing
  • US12518762B2 patent drawing

AI summary

A method includes obtaining a multi-utterance training sample that includes audio data characterizing utterances spoken by two or more different speakers and obtaining ground-truth speaker change intervals indicating time intervals in the audio data where speaker changes among the two or more different speakers occur. The method also includes processing the audio data to generate a sequence of predicted speaker change tokens using a sequence transduction model. For each corresponding predicted speaker change token, the method includes labeling the corresponding predicted speaker change token as correct when the predicted speaker change token overlaps with one of the ground-truth speaker change intervals. The method also includes determining a precision metric of the sequence transduction model based on a number of the predicted speaker change tokens labeled as correct and a total number of the predicted speaker change tokens in the sequence of predicted speaker change tokens.