本論文主要是研究專業型筆記型電腦之噪音問題，針對筆記型電腦在使用中所產生的噪音，經由頻譜分析之後找出主要噪音來源，並發展出一個可以降低筆記型電腦噪音的改善流程，以供日後分析與解決噪音問題之參考。
流程中首先量測筆記型電腦主要的噪音來源並加以分析，確定主要的噪音來源為散熱風扇，接著對風扇入風口結構、出風口鰭片結構以及VGA散熱風扇降低轉速的噪音改善方案。
研究結果顯示，對風扇入風口結構之改善方案使噪音降低了2.4 dB(A)；對風扇出風口鰭片之改善方案使噪音降低了2.9 dB(A)；對VGA散熱風扇降低轉速之改善方案使噪音降低了5.3 dB(A)，而最後將前述三個改善方案合併執行，更可以將筆記型電腦的噪音值降低了5.9 dB(A)，達到預定的目標。

This thesis studied the noise issue of a notebook computer. Frequency spectral analysis was used to locate the main noise sources and a flow chart was established accordingly based on the work involved in the noise improvement process.
The noise from the notebook computer was first measured and the main noise sources were identified as the four cooling fans (one system fan, one CPU fan and two VGA fans).
The results from this study showed that the noise was reduced by 2.4 dB(A) after the inlet cover of the system fan was opened. After the spacing between cooling fins of heat sink was doubled, the noise was reduced by 2.9 dB(A). After the two VGA fan speeds were reduced without letting the temperatures of critical parts exceed the specified upper limits, the total noise was reduced by 5.3 dB(A). At last, when the abovementioned three means were combined together, the total noise were reduced by 5.9 dB(A) and reached the preset goal of this project.

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