主動噪音控制技術應用於輕型耳機和枕頭

Active Noise Control Techniques for Light-weight Earphones and Pillows

陳誼瑈(Yi-Rou Chen)

指導教授 ： 張政元 ； 郭森楙

中原大學/電機資訊學院/電機工程研究所/碩士(2017年)

https://doi.org/10.6840/cycu201700183

摘要

本論文將主動噪音控制(Active Noise Control, ANC)之技術結合音訊應用於枕頭與輕型耳機並且分開討論。我們估測次級路徑時致力於使用音樂或者是大自然的聲音來取代白噪音。我們研製三種輕型主動噪音控制耳機分別是，入耳式、耳塞式和耳掛式。關於實作，我們使用擁有內建麥克風KEMAR的耳朵量測這三種主動降噪控制輕型耳機和市售的降噪耳機消噪效果，並且將實驗結果進行比較。實驗結果發現我們研製的輕型主動式降噪耳機比市售的降噪耳機能夠降噪的分貝更多，其中入耳式主動降噪耳機擁有最佳的降噪能力。

關於枕頭，我們將主動噪音控制枕頭整合舒適的音樂，使得枕頭不僅能夠降低風機的噪音還能利用音樂提升睡眠品質。我們應用寬頻的前饋式和式應性回饋式主動噪音控制系統降噪。關於實作，我們使用真實的風機噪音並且在枕頭上創造靜音區，使得人的頭不管移動至甚麼位置都能夠擁有一定的降噪效果。實演結果顯示，前饋式主動噪音控制系統擁比起回饋式主動噪音控制系統擁有較優異的降噪效果。此外，舒適的音用能夠有效的和主動噪音控制系統整合並且達到掩蓋降噪剩餘噪音的效果。

我們將研製的主動噪音控制整合音樂系統應用於耳機和枕頭。使得主動噪音控制系統的降噪效果不會受到音樂的影響以及使得音樂不會被主動噪音控制消除。我們使用頻率掩蓋的技術驗證大自然聲音有能力掩蓋住降噪後剩餘的風機聲。我們利用問卷調查檢視掩蓋噪音成果。我們也借助其他研究文章整理出，流水聲可以提升睡眠品質。

關鍵字

主動式噪音控制、輕型耳機、枕頭、大自然聲音、估測次級路徑、剩餘噪音掩蓋、頻率掩蓋、睡眠品質

並列摘要

This thesis develops applications of audio-integrated active noise control (ANC) for light-weight earphones and pillows. We purpose using music or natural sound to estimate the critical secondary path model instead of extra random noise. Three types of light-weight ANC earphones including in-ear, earbud, and clip phones are developed. Real-time experiments are conducted to evaluate their performance using the built-in microphone inside KEMAR’s ear and compare with commercial-available ANC headphones and earphone. Experimental results show the developed light-weight ANC earphones achieve higher noise reduction than the commercial ANC headphones and earphone, and the in-ear ANC earphone has the best performance.

For pillows, we integrate ANC with comfort sound for canceling wind turbine noise and improving sleep quality. Broadband feedforward and adaptive feedback ANC algorithms are developed for noise reduction. Real-time experiments using the real wind turbine noise are conducted to measure the generated quiet zone that covers entire the pillow to support free head movement. Experimental results show the feedforward ANC system achieves better performance than the feedback ANC system, and the multiple-channel Feedforward ANC generates larger quiet zone than single-channel systems.

We develop audio integration with ANC for the light-weight earphones and the pillows. The ANC performance will not be degraded by the audio, and the audio will not be canceled by the ANC system. We use frequency masking technique to show the natural sound can effectively mask the residual wind turbine noise. We use subjective evaluation to examine the performance of the residual wind turbine noise masking results. We also cite some researches prove that listening to water fall sound (natural sound) can improve the sleeping quality.

並列關鍵字

Active noise control, light-weight earphone, pillow, natural sound, secondary path modeling, residual noise masking, frequency masking, sleep quality

參考文獻

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