Unified Speech Recognition Endpointing With VAD-EOQ Switching

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Solution Overview

Problem

Conventional speech recognition systems face challenges in achieving high-quality voice activity detection (VAD) and end-of-query (EOQ) detection, which are critical for reducing latency and computational burden, especially in battery-powered devices.

Innovation Solution

An end-to-end multitask model integrates a speech recognition model with an endpointer model, sharing layers and being jointly trained to perform both tasks, with a switch connection allowing the endpointer model to operate in VAD and EOQ detection modes, leveraging latent representations generated by the audio encoder.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If separate models are used for speech recognition and endpointing, then each model can be optimized independently, but the system complexity increases and latency increases

Engineering Contradiction:
Improveendpointing accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines speech recognition and endpointing into a single unified model that performs both functions simultaneously. The model integrates an audio encoder, decoder, and endpointer components that work together to achieve both speech recognition and endpoint detection without requiring separate independent models, thereby reducing system complexity while maintaining functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The unified model serves multiple purposes: it performs speech recognition to transcribe spoken input and simultaneously performs endpointing to detect voice activity and end-of-query points. This multi-functional approach allows a single model to replace what would traditionally require separate specialized models, reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If separate models are used for speech recognition and endpointing, then each model can be optimized independently, but the computational burden increases

Engineering Contradiction:
Improvespeech recognition qualityVSAvoidcomputational burden
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

By merging speech recognition and endpointing into one unified model, the patent eliminates the need to run two separate models, thereby reducing the total computational burden. The shared audio encoder and coordinated processing reduce redundant computations while maintaining the quality of both speech recognition and endpointing functions.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If traditional endpointing methods are used, then implementation is simpler, but latency increases and detection precision decreases

Engineering Contradiction:
Improveimplementation simplicityVSAvoiddetection latency
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The endpointer component continuously monitors audio input and prepares endpoint decisions in real-time during the speech recognition process. This preliminary action allows the system to detect voice activity and end-of-query points without adding significant processing delay, as the endpointing analysis occurs concurrently with speech encoding rather than as a separate post-processing step.

Inventive Principle:
Principle #10Preliminary action

4Ease of operation

If traditional endpointing methods are used, then implementation is simpler, but detection precision decreases

Engineering Contradiction:
Improveimplementation simplicityVSAvoidendpointing accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The unified model uses the audio encoder's latent representations as an intermediary to improve endpointing accuracy. Instead of applying traditional endpointing methods directly to raw audio, the system leverages the encoded audio features and attention mechanisms to make more accurate endpoint decisions, achieving higher precision while maintaining implementation feasibility through the integrated architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS20260100185A1Unified End-To-End Speech Recognition And Endpointing Using A Switch Connection
Publication Date: 2026.04.09 GOOGLE LLC
  • US20260100185A1 patent drawing
  • US20260100185A1 patent drawing
  • US20260100185A1 patent drawing

AI summary

A single E2E multitask model includes a speech recognition model and an endpointer model. The speech recognition model includes an audio encoder configured to encode a sequence of audio frames into corresponding higher-order feature representations, and a decoder configured to generate probability distributions over possible speech recognition hypotheses for the sequence of audio frames based on the higher-order feature representations. The endpointer model is configured to operate between a VAD mode and an EOQ detection mode. During the VAD mode, the endpointer model receives input audio frames, and determines, for each input audio 10 frame, whether the input audio frame includes speech. During the EOQ detection mode, the endpointer model receives latent representations for the sequence of audio frames output from the audio encoder, and determines, for each of the latent representation, whether the latent representation includes final silence.