A Piezoelectric Micromachined Ultrasonic Transducer-Based Bone Conduction Microphone System for Enhancing Speech Recognition Accuracy

Speech recognition in noisy environments has long posed a challenge. Air conduction microphone (ACM), the devices typically used, are susceptible to environmental noise. In this work, a customized bone conduction microphone (BCM) system based on a piezoelectric micromachined ultrasonic transducer is...

Full description

Saved in:
Bibliographic Details
Main Authors: Chongbin Liu, Xiangyang Wang, Jianbiao Xiao, Jun Zhou, Guoqiang Wu
Format: Article
Language:English
Published: MDPI AG 2025-05-01
Series:Micromachines
Subjects:
Online Access:https://www.mdpi.com/2072-666X/16/6/613
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850167793854447616
author Chongbin Liu
Xiangyang Wang
Jianbiao Xiao
Jun Zhou
Guoqiang Wu
author_facet Chongbin Liu
Xiangyang Wang
Jianbiao Xiao
Jun Zhou
Guoqiang Wu
author_sort Chongbin Liu
collection DOAJ
description Speech recognition in noisy environments has long posed a challenge. Air conduction microphone (ACM), the devices typically used, are susceptible to environmental noise. In this work, a customized bone conduction microphone (BCM) system based on a piezoelectric micromachined ultrasonic transducer is developed to capture speech through real-time bone conduction (BC), while a commercial ACM is integrated for simultaneous capture of speech through air conduction (AC). The system enables simpler and more robust BC speech capture. The BC speech capture achieves a signal-to-noise amplitude ratio over five times greater than that of AC speech capture in an environment with a noise level of 68 dB. Instead of using only AC-captured speech, both BC- and AC-captured speech are input into a speech enhancement module. The noise-insensitive BC-captured speech serves as a speech reference to adapt the SE backbone of AC-captured speech. The two types of speech are fused, and noise suppression is applied to generate enhanced speech. Compared with the original noisy speech, the enhanced speech achieves a character error rate reduction of over 20%, approaching the speech recognition accuracy of clean speech. The results indicate that this speech enhancement method based on the fusion of BC- and AC-captured speech efficiently integrates the features of both types of speech, thereby improving speech recognition accuracy in noisy environments. This work presents an innovative system designed to efficiently capture BC speech and enhance speech recognition in noisy environments.
format Article
id doaj-art-b0b671d9f3b445479bf0ed13e543f12a
institution OA Journals
issn 2072-666X
language English
publishDate 2025-05-01
publisher MDPI AG
record_format Article
series Micromachines
spelling doaj-art-b0b671d9f3b445479bf0ed13e543f12a2025-08-20T02:21:07ZengMDPI AGMicromachines2072-666X2025-05-0116661310.3390/mi16060613A Piezoelectric Micromachined Ultrasonic Transducer-Based Bone Conduction Microphone System for Enhancing Speech Recognition AccuracyChongbin Liu0Xiangyang Wang1Jianbiao Xiao2Jun Zhou3Guoqiang Wu4The Institute of Technological Sciences, Wuhan University, Wuhan 430072, ChinaThe Institute of Technological Sciences, Wuhan University, Wuhan 430072, ChinaSchool of Information and Communication Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu 611731, ChinaSchool of Information and Communication Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu 611731, ChinaThe Institute of Technological Sciences, Wuhan University, Wuhan 430072, ChinaSpeech recognition in noisy environments has long posed a challenge. Air conduction microphone (ACM), the devices typically used, are susceptible to environmental noise. In this work, a customized bone conduction microphone (BCM) system based on a piezoelectric micromachined ultrasonic transducer is developed to capture speech through real-time bone conduction (BC), while a commercial ACM is integrated for simultaneous capture of speech through air conduction (AC). The system enables simpler and more robust BC speech capture. The BC speech capture achieves a signal-to-noise amplitude ratio over five times greater than that of AC speech capture in an environment with a noise level of 68 dB. Instead of using only AC-captured speech, both BC- and AC-captured speech are input into a speech enhancement module. The noise-insensitive BC-captured speech serves as a speech reference to adapt the SE backbone of AC-captured speech. The two types of speech are fused, and noise suppression is applied to generate enhanced speech. Compared with the original noisy speech, the enhanced speech achieves a character error rate reduction of over 20%, approaching the speech recognition accuracy of clean speech. The results indicate that this speech enhancement method based on the fusion of BC- and AC-captured speech efficiently integrates the features of both types of speech, thereby improving speech recognition accuracy in noisy environments. This work presents an innovative system designed to efficiently capture BC speech and enhance speech recognition in noisy environments.https://www.mdpi.com/2072-666X/16/6/613microelectromechanical systems (MEMS)piezoelectric micromachinedultrasonic transducer (PMUT)bone conduction microphonespeech enhancement
spellingShingle Chongbin Liu
Xiangyang Wang
Jianbiao Xiao
Jun Zhou
Guoqiang Wu
A Piezoelectric Micromachined Ultrasonic Transducer-Based Bone Conduction Microphone System for Enhancing Speech Recognition Accuracy
Micromachines
microelectromechanical systems (MEMS)
piezoelectric micromachinedultrasonic transducer (PMUT)
bone conduction microphone
speech enhancement
title A Piezoelectric Micromachined Ultrasonic Transducer-Based Bone Conduction Microphone System for Enhancing Speech Recognition Accuracy
title_full A Piezoelectric Micromachined Ultrasonic Transducer-Based Bone Conduction Microphone System for Enhancing Speech Recognition Accuracy
title_fullStr A Piezoelectric Micromachined Ultrasonic Transducer-Based Bone Conduction Microphone System for Enhancing Speech Recognition Accuracy
title_full_unstemmed A Piezoelectric Micromachined Ultrasonic Transducer-Based Bone Conduction Microphone System for Enhancing Speech Recognition Accuracy
title_short A Piezoelectric Micromachined Ultrasonic Transducer-Based Bone Conduction Microphone System for Enhancing Speech Recognition Accuracy
title_sort piezoelectric micromachined ultrasonic transducer based bone conduction microphone system for enhancing speech recognition accuracy
topic microelectromechanical systems (MEMS)
piezoelectric micromachinedultrasonic transducer (PMUT)
bone conduction microphone
speech enhancement
url https://www.mdpi.com/2072-666X/16/6/613
work_keys_str_mv AT chongbinliu apiezoelectricmicromachinedultrasonictransducerbasedboneconductionmicrophonesystemforenhancingspeechrecognitionaccuracy
AT xiangyangwang apiezoelectricmicromachinedultrasonictransducerbasedboneconductionmicrophonesystemforenhancingspeechrecognitionaccuracy
AT jianbiaoxiao apiezoelectricmicromachinedultrasonictransducerbasedboneconductionmicrophonesystemforenhancingspeechrecognitionaccuracy
AT junzhou apiezoelectricmicromachinedultrasonictransducerbasedboneconductionmicrophonesystemforenhancingspeechrecognitionaccuracy
AT guoqiangwu apiezoelectricmicromachinedultrasonictransducerbasedboneconductionmicrophonesystemforenhancingspeechrecognitionaccuracy
AT chongbinliu piezoelectricmicromachinedultrasonictransducerbasedboneconductionmicrophonesystemforenhancingspeechrecognitionaccuracy
AT xiangyangwang piezoelectricmicromachinedultrasonictransducerbasedboneconductionmicrophonesystemforenhancingspeechrecognitionaccuracy
AT jianbiaoxiao piezoelectricmicromachinedultrasonictransducerbasedboneconductionmicrophonesystemforenhancingspeechrecognitionaccuracy
AT junzhou piezoelectricmicromachinedultrasonictransducerbasedboneconductionmicrophonesystemforenhancingspeechrecognitionaccuracy
AT guoqiangwu piezoelectricmicromachinedultrasonictransducerbasedboneconductionmicrophonesystemforenhancingspeechrecognitionaccuracy