Speaker-Conditioned Voice Filtering for Overlapping Speech Isolation

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Solution Overview

Problem

Existing automated assistants struggle to accurately isolate and process voice data from a single speaker amidst background noise and overlapping voices, leading to inaccuracies in voice-to-text conversion and interactive dialog responses.

Innovation Solution

A trained voice filter model generates a predicted mask using speaker embeddings to isolate the voice of a single speaker by processing audio spectrograms, employing convolutional and recurrent neural networks to refine the audio data and remove background noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional speech recognition processes audio data directly, then processing speed is maintained, but voice isolation accuracy deteriorates due to background noise and overlapping voices

Engineering Contradiction:
Improvevoice isolation accuracyVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the audio processing task into distinct stages: first generating a spectrogram from the audio signal, then creating a predicted mask to isolate the target speaker's voice, and finally converting the masked spectrogram back to audio. This segmentation allows each stage to specialize in a specific function, improving voice isolation accuracy while managing processing complexity through modular architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces intermediate representations (spectrogram and predicted mask) as mediators between the raw audio data and the final isolated voice output. The spectrogram transforms audio into a visual frequency-time representation, and the predicted mask acts as a filter that selectively enhances target speaker components. These intermediaries enable more accurate voice isolation by operating in a transformed domain where speaker characteristics are more distinguishable.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If speaker embeddings are used to condition the voice filter model, then voice isolation precision is improved, but computational requirements increase

Engineering Contradiction:
Improvespeaker identification accuracyVSAvoidcomputational energy
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent performs preliminary extraction of speaker embeddings from audio data before using them to condition the voice filter model. By pre-computing these embeddings that capture speaker-specific characteristics, the system prepares targeted information in advance that guides the masking process. This preliminary action improves speaker identification accuracy while allowing the main processing to focus on voice isolation rather than speaker analysis.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS12469498B2Targeted voice separation by speaker conditioned on spectrogram masking
Publication Date: 2025.11.11 GOOGLE LLC
  • US12469498B2 patent drawing
  • US12469498B2 patent drawing
  • US12469498B2 patent drawing

AI summary

Techniques are disclosed that enable processing of audio data to generate one or more refined versions of audio data, where each of the refined versions of audio data isolate one or more utterances of a single respective human speaker. Various implementations generate a refined version of audio data that isolates utterance(s) of a single human speaker by processing a spectrogram representation of the audio data (generated by processing the audio data with a frequency transformation) using a mask generated by processing the spectrogram of the audio data and a speaker embedding for the single human speaker using a trained voice filter model. Output generated over the trained voice filter model is processed using an inverse of the frequency transformation to generate the refined audio data.