CV

General information

Experience

• 2026-04 – present

  Full-time Engineer

  LY Corporation

  Japan

• 2024-12 – 2026-03

  Part-time Researcher

  LY Corporation R&D

  Japan

  • Improved phonemic and prosodic annotation models for text-to-speech; the work was accepted to Interspeech 2025.
  • Researched neural vocoders for high-quality speech generation from self-supervised speech features; the work was accepted to ICASSP 2026.
• 2025-02 – 2025-03

  Research Intern

  NTT Communication Science Laboratories

  Japan

  • Researched post-refinement of ASR hypotheses for joint multi-channel distant speech recognition.
• 2024-08 – 2024-10

  Research Intern

  LY Corporation R&D

  Japan

  • Improved phonemic and prosodic annotation models for text-to-speech and related subtasks.
• 2022-06 – 2022-07

  Research Intern

  The University of Tokyo

  Japan

  • Researched environmental sound synthesis from visual onomatopoeia; the work was accepted to ICASSP 2023.

Education

• 2024-04 – 2026-03

  Nara Institute of Science and Technology

  M.S., Information Science

  Japan

  • Graduate School of Science and Technology, Master's Course.
  • Intelligent Robot Dialogue Laboratory (RIKEN), supervised by Prof. Koichiro Yoshino.
  • Received the NAIST Best Student Award.
• 2022-04 – 2024-03

  National Institute of Technology, Tokuyama College

  Computer Science and Electronic Engineering

  Japan

  • Advanced Course.
  • Miyazaki Laboratory, supervised by Prof. Ryoichi Miyazaki.
• 2017-04 – 2022-03

  National Institute of Technology, Tokuyama College

  Computer Science and Electronic Engineering

  Japan

  • Regular Course.
  • Miyazaki Laboratory, supervised by Prof. Ryoichi Miyazaki.

Selected Publications

• Accepted 2026

  Wave-Trainer-Fit: Neural Vocoder with Trainable Prior and Fixed-Point Iteration towards High-Quality Speech Generation from SSL Features

  Hien Ohnaka, Yuma Shirahata, Masaya Kawamura

  IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)

• 2025-08

  Grapheme-Coherent Phonemic and Prosodic Annotation of Speech by Implicit and Explicit Grapheme Conditioning

  Hien Ohnaka, Yuma Shirahata, Byeongseon Park, Ryuichi Yamamoto

  Interspeech

• 2025-02

  Unsupervised Speech Enhancement with Spectral Kurtosis and Double Deep Priors

  Hien Ohnaka, Ryoichi Miyazaki

  Acoustical Science and Technology

• 2023-06

  Visual Onoma-to-Wave: Environmental Sound Synthesis from Visual Onomatopoeias and Sound-Source Images

  Hien Ohnaka, Shinnosuke Takamichi, Keisuke Imoto, Yuki Okamoto, Kazuki Fujii, Hiroshi Saruwatari

  IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)

Awards

• 2026-03

  Best Student Award

  Awarded by Nara Institute of Science and Technology. Announcement

• 2025-03

  Committee Special Award

  Awarded by the Association for Natural Language Processing for work on jointly predicting response timing and short responses for real-time spoken dialogue systems. Award details

Research Projects

• 2025 – 2026

  Wave-Trainer-Fit

  A neural vocoder with trainable priors and fixed-point iteration for high-quality speech generation from self-supervised speech features.

  • Accepted to ICASSP 2026.
• 2024 – 2025

  Unsupervised Speech Enhancement with Spectral Kurtosis and Double Deep Priors

  An unsupervised speech enhancement method combining spectral kurtosis and deep priors.

  • Published in Acoustical Science and Technology.
• 2022 – 2023

  Visual Onoma-to-Wave

  Environmental sound synthesis from visual onomatopoeias and sound-source images.

  • Accepted to ICASSP 2023.