以往關於時常的分析大體都是基於少量幾個發音人的有限語料。這樣就很難區分這些研究結果到底反映的是所研究語言的一般特徵，還是發音人的個人特徵。由於這個原因，它們很難被直接運用到當今的語音科技。
在本文中，我們利用錄自大量發音人的大型連續語音數據庫來考察自然語流中普通話和廣東話（香港廣東話）的時長特徵。我們發現：在普通話和廣東話中，聲母時長和韻母時長不存在明顯的補償作用（零聲母情況除外）；廣東話音節時長變化小於普通話，因而具有相對比較好的音節等時性。
Previous studies on temporal aspects of languages are usually based on limited data from a small number of subjects. It is difficult to know whether these findings can really represent the general temporal aspects of continuous speech, or just the speech of the specific subjects involved. Because of this difficulty it may not be appropriate to directly apply these findings to current speech technologies.
In this study, large vocabulary continuous speech databases for Mandarin and Cantonese, recorded from large populations of subjects, are used to investigate the temporal aspects of syllables in continuous speech. Our findings include the following. No obvious temporal compensation effect has been found between the syllable initial (null initial being the sole exception) and the syllable final; Cantonese syllables exhibit less variation than Mandarin, achieving better isochrony.