Keyword Spotting Neural Network Depthwise Pointwise Convolution

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Solution Overview

Problem

Conventional keyword spotting systems face a trade-off between high accuracy and low latency, requiring significant computational resources, which is particularly challenging on mobile devices where real-time performance is essential.

Innovation Solution

The proposed solution involves a keyword spotting method using a temporal convolutional neural network (TC-ResNet) that applies 1D convolution along the temporal dimension, treating mel-frequency cepstral coefficients (MFCC) as input channels, reducing the number of operations and enhancing accuracy while maintaining a compact architecture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional convolution-based keyword spotting is used, then accuracy is improved, but computational complexity and latency increase significantly

Engineering Contradiction:
Improvekeyword spotting accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the convolution operation into depthwise convolution and pointwise convolution stages. The depthwise convolution applies separate filters to each input channel, and the pointwise convolution combines the results using 1x1 convolutions. This segmentation reduces the total number of computations while maintaining accuracy, directly resolving the contradiction between accuracy and computational complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the dimensionality of the convolution operation by applying filters along the depth dimension rather than treating all channels uniformly. This dimensional approach allows for more efficient computation by processing channels independently and then combining results, reducing computational complexity while preserving the accuracy needed for keyword spotting.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If traditional convolution-based keyword spotting is used, then accuracy is improved, but processing speed decreases

Engineering Contradiction:
Improvekeyword spotting accuracyVSAvoidkeyword extraction speed
Core Design Contradiction:
Measurement precisionVSSpeed

Solution Approach 1:

By segmenting the convolution into depthwise and pointwise operations, the patent enables more efficient parallel processing. The depthwise convolution processes each channel independently, and the pointwise convolution combines results efficiently, significantly improving processing speed while maintaining the accuracy required for keyword spotting.

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If traditional convolution-based keyword spotting is used, then accuracy is improved, but resource consumption increases

Engineering Contradiction:
Improvekeyword spotting accuracyVSAvoidcomputational resource consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The segmentation of convolution operations reduces the total computational load, directly decreasing energy consumption and resource usage. By processing channels independently in the depthwise stage and combining results efficiently in the pointwise stage, the patent maintains accuracy while significantly reducing the computational resources required.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS11854536B2Keyword spotting apparatus, method, and computer-readable recording medium thereof
Publication Date: 2023.12.26 HYPERCONNECT INC
  • US11854536B2 patent drawing
  • US11854536B2 patent drawing
  • US11854536B2 patent drawing

AI summary

A keyword spotting apparatus, method, and computer-readable recording medium are disclosed. The keyword spotting method using an artificial neural network according to an embodiment of the disclosure may include obtaining an input feature map from an input voice; performing a first convolution operation on the input feature map for each of n different filters having the same channel length as the input feature map, wherein a width of each of the filters is w1 and the width w1 is less than a width of the input feature map; performing a second convolution operation on a result of the first convolution operation for each of different filters having the same channel length as the input feature map; storing a result of the second convolution operation as an output feature map; and extracting a voice keyword by applying the output feature map to a learned machine learning model.