聲場混響時間為評估封閉空間內部聲學特性的重要參數，一般定義為空間內部聲源停止發聲後，聲音強度由初始強度下降60分貝所需的時間，根據聲音強度衰減曲線的生成方式不同，大致可區分為直接量測衰減曲線之噪音中斷法，以及間接量測衰減曲線之脈衝響應積分法。本研究針對單頻訊號、最大長度序列訊號應用於噪音中斷法，以及最大長度序列訊號、指數掃頻訊號應用於脈衝響應積分法，於大型演講堂、一般教室等空氣環境中進行混響時間衰減量測，討論各種訊號處理參數(如：訊號週期長度、步階長度)對於混響時間估測的影響。此外，更進一步將混響時間衰減量測技術應用於水下環境，評估水中材料的吸音效益，水下實驗於本系之拖航水槽中進行，結果顯示出各種方法對於混響時間估測的一致性，皆可有效運用於水中材料之吸音率評估，但使用寬頻訊號(最大長度序列訊號與指數掃頻訊號)可在相同準確性下，大幅縮短量測時間，提高整體試驗效率。

Reverberation time is an important parameter for evaluating the acoustic characteristics of enclosed spaces. It is generally defined as the time requirement of the sound intensity from initial intensity to decreasing 60 decibels after the sound source stops emitted. Depending on how the sound intensity decay curve is generated, it can be roughly divided into the noise interruption method with direct measurement of the decay curve, and the impulse response integration method with indirect measurements of the decay curve. This study focuses on applying single-frequency signals and maximum length sequence signals to the noise interruption method. In addition to implementing the maximum length sequence signals and exponential sweep signals to the impulse response integration method. Reverberation time decay measurements were conducted in various environments such as auditorium or general classrooms. The study discusses the impact of various signal processing parameters (e.g., signal period length, and step length) on the estimation of reverberation time. This study further applicated reverberation time decay measurement techniques to underwater environments to evaluate the sound absorption efficiency of underwater materials. The results show the consistency of various methods in estimating reverberation time, which indicates that they can be effectively used to evaluate the absorption coefficient of underwater materials. However, using broadband signals (maximum length sequence signals and exponential sweep signals) can significantly shorten the measurement time while maintaining the same accuracy, thereby improving overall experimental efficiency.

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