Hwai-Tsu Chang

Title: **Innovative Contributions of Hwai-Tsu Chang in Speech Enhancement Technologies**

Introduction

Hwai-Tsu Chang, an accomplished inventor based in Hsinchu, Taiwan, has made significant contributions to the field of speech enhancement. With a total of seven patents, his innovative solutions specifically focus on enhancing the quality of speech signals affected by noise, employing advanced filtering techniques. His work has broader implications in various applications, from telecommunications to audio processing technologies.

Latest Patents

Among Hwai-Tsu Chang's notable patents are two recent innovations that exemplify his expertise in speech processing:

1. **Frame-based subband Kalman filtering method and apparatus for speech enhancement**

This invention presents a method and apparatus designed to enhance speech signals that have been contaminated by additive noise utilizing Kalman filtering. The process begins by decomposing the speech signal into subband signals through a multichannel analysis filter bank. Following this, low-order Kalman filters are applied to each subband signal to improve the clarity of speech. The method estimates autoregression parameters on a frame-by-frame basis, ultimately synthesizing enhanced fullband speech signals.

2. **Method of amplitude coding for low bit rate sinusoidal transform vocoder**

This invention focuses on a sinusoidal transform vocoder developed based on the Bark spectrum. It provides high-quality sound coding at a low bit rate by transforming harmonic sine waves from the frequency spectrum to a perception-based Bark spectrum. This method optimizes the coding of subjective loudness through equal-loudness pre-emphasis and pulse code modulation, which are integral for achieving clear voice transmissions.

Career Highlights

Hwai-Tsu Chang is affiliated with the Industrial Technology Research Institute, where he has spearheaded innovative projects that push the boundaries of speech processing technologies. His expertise in developing practical solutions that cater to modern communication challenges has placed him at the forefront of research and development in this domain.

Collaborations

Throughout his career, Hwai-Tsu Chang has collaborated with esteemed colleagues, including Tzi-Dar Chiueh and Wan-Yu Meng. These partnerships have facilitated the exchange of ideas and expertise, further enriching his contributions to the field and resulting in several impactful innovations.

Conclusion

In summary, Hwai-Tsu Chang is a distinguished inventor whose innovative work in speech enhancement technologies has garnered him several patents. His latest contributions, utilizing advanced filtering methods and sound coding techniques, highlight his commitment to improving communication systems. As he continues to innovate, Hwai-Tsu Chang remains an influential figure in the realm of speech processing and technology development.