Speech Enhancement System Codec Compatibility

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing speech enhancement systems often produce output signals that do not match the expected speech models of succeeding speech encoders or decoders, leading to sub-optimal encoding and generation of undesired artifacts like noise gating and lower quality speech.

Innovation Solution

A speech enhancement system that converts sound waves into operational signals, selects a template representing an expected signal model through a shared speech codebook accessed in a communication channel, and integrates with speech encoders and decoders to match encoding and decoding characteristics, minimizing mismatches and artifacts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If speech enhancement systems process signals independently without considering encoder/decoder models, then direct audition quality is improved, but compatibility with speech codecs deteriorates causing sub-optimal encoding and artifacts

Engineering Contradiction:

Improvedirect audition qualityVSAvoidcodec compatibility

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent introduces a compatibility layer that acts as an intermediary between the speech enhancement system and the speech codec. This layer transforms the enhanced speech signal into a form that matches the expected input model of the codec, preventing mismatches and artifacts while preserving the quality improvements from enhancement.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically adjusts signal parameters based on the specific codec being used. By changing parameters such as spectral shape, temporal envelope, and other codec-specific characteristics, the enhanced speech signal is adapted to match the expected input model of different codecs, resolving the compatibility issue.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If speech enhancement aggressively removes noise, then noise gating artifacts are reduced, but speech quality and naturalness deteriorate

Engineering Contradiction:

Improvenoise gating artifactsVSAvoidspeech quality

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

Instead of completely removing all noise components, the system applies partial enhancement by selectively attenuating noise in specific time-frequency regions where it does not interfere with speech perception. This partial action approach maintains speech naturalness while still reducing noise gating artifacts.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The system uses feedback mechanisms to monitor the enhanced speech signal and adjust the enhancement parameters dynamically. By comparing the enhanced output with the original signal and the expected codec input model, the system fine-tunes the enhancement strength to prevent over-processing that would degrade speech quality.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS8326614B2Speech enhancement system

Publication Date: 2012.12.04 BLACKBERRY LTD

AI summary

A speech enhancement system improves speech conversion within an encoder and decoder. The system includes a first device that converts sound waves into operational signals. A second device selects a template that represents an expected signal model. The selected template models speech characteristics of the operational signals through a speech codebook that is further accessed in a communication channel.