Speech Endpoint Detection Using Silent Phoneme Frame Counting

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Solution Overview

Problem

Current automatic speech recognition (ASR) systems face challenges in efficient decoding and endpoint detection due to high computational requirements and bandwidth usage, with traditional endpointing techniques being imprecise, especially in the presence of background noise and non-speech events.

Innovation Solution

Implementing a hybrid decoding approach using a WFST accelerator with hardware components for local processing of acoustic features and a personalized grammar model, along with an endpointing module to accurately detect speech endpoints by counting silent frames and utilizing a threshold-based method.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional endpointing techniques are used, then the system is simple to implement, but the endpoint detection precision deteriorates in the presence of background noise and non-speech events

Engineering Contradiction:
Improveendpoint detection precisionVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The endpoint detection function is segmented into a dedicated hardware module within the WFST accelerator, separating it from the main processing pipeline. This dedicated module independently counts silent frames and detects endpoints, improving precision without significantly increasing overall system complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A silent frame counter is introduced as an intermediary component that tracks the number of consecutive silent frames. This counter acts as a mediator between the audio input and endpoint detection logic, providing a quantitative basis for more accurate endpoint detection in noisy environments.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If all speech data is processed remotely via server, then comprehensive processing can be performed, but bandwidth usage and processing time increase

Engineering Contradiction:
Improvedecoding speedVSAvoidprocessing time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The endpoint detection function is extracted from the remote server processing and implemented locally within the WFST accelerator hardware. This extraction enables the system to autonomously determine speech endpoints without continuous server communication, significantly reducing bandwidth usage and processing time while maintaining decoding speed.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If the speech recognition system processes all audio data continuously, then no speech is missed, but computational resources are wasted during silent periods

Engineering Contradiction:
Improvespeech recognition reliabilityVSAvoidcomputational energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary action by counting silent frames before triggering endpoint detection. This preliminary counting mechanism allows the system to anticipate the end of speech segments and pause processing during confirmed silent periods, reducing energy consumption while maintaining reliability through the threshold-based detection approach.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS11056098B1Silent phonemes for tracking end of speech
Publication Date: 2021.07.06 AMAZON TECH INC
  • US11056098B1 patent drawing
  • US11056098B1 patent drawing
  • US11056098B1 patent drawing

AI summary

Embodiments describe a method for speech endpoint detection including receiving identification data for a first state associated with a first frame of speech data from a WFST language model, determining that the first frame of the speech data includes silence data, incrementing a silence counter associated with the first state, copying a value of the silence counter of the first state to a corresponding silence counter field in a second state associated with the first state in an active state list, and determining that the value of the silence counter for the first state is above a silence threshold. The method further includes, determining that an endpoint of the speech has occurred in response to determining that the silence counter is above the silence threshold, and outputting text data representing a plurality of words determined from the speech data that was received prior to the endpoint.