Conformer-Based Speech Conversion With Typical-Speech Pretraining

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Solution Overview

Problem

Current speech conversion models struggle to effectively train on insufficient data from speakers with speech impairments, making it difficult to convert atypical speech into canonical fluent speech, especially for conditions like ALS, heavily-accented speech, and deaf speech, due to the challenges in obtaining sufficient training data and maintaining optimal performance.

Innovation Solution

A Conformer-based speech conversion model with an encoder and decoder architecture that includes subsampling and upsampling layers, allowing for less data-intensive training and robust conversion of atypical speech into canonical fluent speech, using a two-step training process to pre-train on typical speakers and fine-tune for atypical speakers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional speech conversion models are used to convert atypical speech into canonical fluent speech, then the conversion capability is provided, but the models require extensive training data from speakers with speech impairments which is insufficient and difficult to obtain

Engineering Contradiction:
Improvespeech conversion capabilityVSAvoidtraining data quantity
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The model is pre-trained on abundant data from typical speakers before being fine-tuned on limited atypical speech data. This preliminary training establishes a strong foundation that enables effective learning from scarce atypical speech examples, resolving the contradiction between needing reliable conversion capability and lacking sufficient training data.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The model employs frame rate conversion and temporal downsampling to change the temporal parameters of speech processing. By processing speech at different frame rates and then converting back, the model learns robust representations that generalize better from limited atypical speech data, improving conversion reliability without requiring more training data.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If more training data from atypical speakers is collected to improve conversion accuracy, then the speech conversion quality improves, but the complexity of data collection and processing increases

Engineering Contradiction:
Improvespeech conversion accuracyVSAvoiddata collection and processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

By pre-training on typical speech data before fine-tuning on atypical speech, the model reduces the amount of atypical speech data needed for effective training. This two-stage approach simplifies the overall data collection process while maintaining high conversion accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The model uses an intermediate representation space created during pre-training that bridges typical and atypical speech. This intermediate representation acts as a mediator that enables effective learning from limited atypical speech data without requiring complex data processing pipelines.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If the model processes speech at high frame rates to maintain temporal resolution, then the speech quality is preserved, but the computational complexity and training data requirements increase

Engineering Contradiction:
Improvespeech qualityVSAvoidcomputational complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The model processes speech at varying frame rates, using lower frame rates during certain processing stages and higher frame rates at others. This periodic variation in processing intensity maintains speech quality where needed while reducing computational complexity overall, avoiding the need for consistently high-rate processing.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The model dynamically changes temporal parameters through frame rate conversion and temporal downsampling. By adjusting the temporal resolution parameter at different processing stages, the model maintains speech quality when necessary while reducing computational complexity during other stages.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS20250285609A1Conformer-based Speech Conversion Model
Publication Date: 2025.09.11 GOOGLE LLC
  • US20250285609A1 patent drawing
  • US20250285609A1 patent drawing
  • US20250285609A1 patent drawing

AI summary

A method for speech conversion includes receiving, as input to an encoder of a speech conversion model, an input spectrogram corresponding to an utterance, the encoder including a stack of self-attention blocks. The method further includes generating, as output from the encoder, an encoded spectrogram and receiving, as input to a spectrogram decoder of the speech conversion model, the encoded spectrogram generated as output from the encoder. The method further includes generating, as output from the spectrogram decoder, an output spectrogram corresponding to a synthesized speech representation of the utterance.