Cited by 227Speech Recognition and SynthesisSpeech and Audio ProcessingEEG and Brain-Computer Interfaces

Speech synthesis from ECoG using densely connected 3D convolutional neural networks

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Angrick, Miguel, Herff, Christian, Mugler, Emily, Tate, Matthew C, Slutzky, Marc W, Krusienski, Dean J, Schultz, Tanja·2019·Journal of Neural Engineering

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Abstract

Objective . Direct synthesis of speech from neural signals could provide a fast and natural way of communication to people with neurological diseases. Invasively-measured brain activity (electrocorticography; ECoG) supplies the necessary temporal and spatial resolution to decode fast and complex processes such as speech production. A number of impressive advances in speech decoding using neural signals have been achieved in recent years, but the complex dynamics are still not fully understood. However, it is unlikely that simple linear models can capture the relation between neural activity and continuous spoken speech. Approach . Here we show that deep neural networks can be used to map ECoG from speech production areas onto an intermediate representation of speech (logMel spectrogram). The proposed method uses a densely connected convolutional neural network topology which is well-suited to work with the small amount of data available from each participant. Main results . In a study with six participants, we achieved correlations up to r = 0.69 between the reconstructed and original logMel spectrograms. We transfered our prediction back into an audible waveform by applying a Wavenet vocoder. The vocoder was conditioned on logMel features that harnessed a much larger, pre-existing data corpus to provide the most natural acoustic output. Significance . To the best of our knowledge, this is the first time that high-quality speech has been reconstructed from neural recordings during speech production using deep neural networks.

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  • Prior work has synthesized intelligible speech from neural activity during vocalized or mimed speech in speakers with intact speech, but not in a paralysed person.

    “Previous work in speakers with intact speech has demonstrated that intelligible speech can be synthesized from neural activity during vocalized or mimed speech10,11, but this has not been shown with someone who is paralysed.”

    From A high-performance neuroprosthesis for speech decoding and avatar control (2023) · cites this paper as [10]

    The Discussion (page unavailable) says the study reconstructed high-quality speech from neural recordings during overt speech in motor-intact participants and that speech representations in paralysed patients need further research. The Results (page unavailable) say intelligibility was evaluated with STOI, but the available text does not establish that the synthesized speech was intelligible. This paper studied vocalized speech, not mimed speech. (LLM, conf=0.78)

    Experimental — accuracy not yet measured
  • Angrick et al. and Anumanchipalli et al. used a two-stage decoding process in which a deep-learning model regresses neural activity to acoustic features and a vocoder converts them to audible speech.

    “Another approach, pursued by Angrick et al.111 and Anumanchipalli et al.110, involved a two-stage decoding process. In the first stage, a deep-learning model is trained to regress neural activity (recorded from SEEG111 or ECoG110) to a time series of acoustic features, such as the mel-spectrogram (Fig. 3b). In the second stage, a speech synthesizer — a vocoder — is used to convert the acoustic rep”

    From The speech neuroprosthesis (2024) · cites this paper as [111]

    The Decoding Approach section describes the claimed two-stage process: a DenseNet maps neural activity to mel-scaled spectrograms, and a WaveNet vocoder produces audio. However, the citing sentence assigns SEEG to Angrick et al.; the Experiment and Data Recording section says they recorded ECoG using a cortical electrode grid. Page numbers are unavailable in our copy. (LLM, conf=0.90)

    Experimental — accuracy not yet measured

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3 of the 76 references couldn’t be matched to a known paper.

Research works printed but not linked: 1

  1. [66]Kalchbrenner N, Elsen E, Simonyan K, Noury S, Casagrande N, Lockhart E, Stimberg F, Oord A. v. d., Dieleman S, and Kavukcuoglu K, “ Efficient neural audio synthesis,” arXiv preprint arXiv: 1802 08435, 2018.

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Authors
Angrick, M., Herff, C., Mugler, E., Tate, M. C., Slutzky, M. W., Krusienski, D. J., & Schultz, T.
Affiliations
  • University of Bremen (DE)
  • Northwestern University (US)
  • Virginia Commonwealth University (US)
Corresponding author
  • Angrick, Miguel
  • Herff, Christian
Venue
Journal of Neural Engineering
Published
2019-04-16
Volume
16
Issue
3
Pages
036019
ISSN
  • 1741-2552 (ISSN-L)
  • 1741-2560
OpenAlex
W2952609044
Cited by
225
References
76
Citations by year
2026: 18 · 2025: 36 · 2024: 35 · 2023: 28 · 2022: 34 · 2021: 30 · 2020: 29 · 2019: 15
FWCI
12.32
Type
journal article
Language
en
Open access
Locations
  • Journal of Neural Engineering (publishedVersion)
  • bioRxiv (Cold Spring Harbor Laboratory) (acceptedVersion)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
  • Research Publications (Maastricht University) (submittedVersion, other-oa)
Funders
  • National Science Foundation (1608140)
  • National Institutes of Health (F32DC015708)
  • National Center for Advancing Translational Sciences (UL1TR000150)
  • Bundesministerium für Bildung und Forschung (01GQ1602)
  • Doris Duke Charitable Foundation (2011039)
Topics
  • Physical Sciences › Computer Science › Artificial Intelligence › Speech Recognition and Synthesis
  • Physical Sciences › Computer Science › Signal Processing › Speech and Audio Processing
  • Life Sciences › Neuroscience › Cognitive Neuroscience › EEG and Brain-Computer Interfaces
Keywords
speech synthesis, electrocorticography, neural speech decoding, 3D convolutional neural networks, speech production, brain-computer interface, augmentative and alternative communication
MeSH terms
Electrocorticography, Cerebral Cortex, Communication Aids for Disabled, Communication Devices for People with Disabilities, Humans, Photic Stimulation, Speech, Neural Networks, Computer

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