Pruned Acoustic Model for Low Resource Key Phrase Detection

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Solution Overview

Problem

Current key phrase detection systems in low resource environments face challenges with robustness due to high complexity, leading to issues with noise and false accepts, making them unsuitable for widespread implementation in wake on voice systems.

Innovation Solution

A method using a pruned deep neural network-based acoustic model, a start state based rejection model, and a key phrase model, which generates a time series of scores for sub-phonetic units to determine the likelihood of a key phrase, reducing resource usage while maintaining detection accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex key phrase detection models (GMMs with context-dependent phones) are used, then detection accuracy is improved, but device complexity and resource consumption increase

Engineering Contradiction:
Improvekey phrase detection accuracyVSAvoidmodel complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and removes unnecessary components from the original complex GMM model, keeping only the essential elements needed for key phrase detection. This involves pruning the model to eliminate redundant context-dependent phone models while retaining the core detection functionality, thereby reducing complexity while maintaining accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies different levels of modeling complexity to different parts of the key phrase detection system. Instead of uniformly complex modeling across all phones, it uses simplified models for non-critical segments and more detailed models only where necessary for accurate detection, optimizing the balance between accuracy and resource usage.

Inventive Principle:
Principle #3Local quality

2Use of energy by moving object

If simpler key phrase detection techniques are used, then resource consumption is reduced, but robustness deteriorates

Engineering Contradiction:
Improvepower consumptionVSAvoidrobustness
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent performs preliminary processing and filtering of audio input before applying the simplified detection model. By pre-processing the signal to enhance relevant features and suppress noise early in the pipeline, the simpler model can achieve robust detection performance without requiring complex post-processing or high computational resources.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent optimizes detection parameters such as threshold values, time windows, and feature extraction parameters to maximize the performance of simplified models. By carefully tuning these parameters, the system achieves robust detection with lower computational complexity and reduced power consumption.

Inventive Principle:
Principle #35Parameter changes

3Use of energy by stationary object

If current low resource techniques are used, then power consumption is reduced, but false accepts increase

Engineering Contradiction:
Improvepower usageVSAvoiddetection precision
Core Design Contradiction:
Use of energy by stationary objectVSMeasurement precision

Solution Approach 1:

The patent introduces intermediary verification steps and additional features that act as mediators between the simplified detection model and the final decision. These intermediaries provide extra validation without requiring full complex model execution, thereby reducing false accepts while maintaining low power consumption.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS10325594B2Low resource key phrase detection for wake on voice
Publication Date: 2019.06.18 INTEL CORP
  • US10325594B2 patent drawing
  • US10325594B2 patent drawing
  • US10325594B2 patent drawing

AI summary

Techniques related to key phrase detection for applications such as wake on voice are discussed. Such techniques may include updating a start state based rejection model and a key phrase model based on scores of sub-phonetic units from an acoustic model to generate a rejection likelihood score and a key phrase likelihood score and determining whether received audio input is associated with a predetermined key phrase based on the rejection likelihood score and the key phrase likelihood score.