Previously published studies on the role of amplitude envelope in lexical tone perception focused on Mandarin only. Amplitude envelope was found to co-vary with fundamental frequency in Mandarin lexical tones, and amplitude envelope alone could cue tone perception in Mandarin which uses primarily tone contour for phonemic tonal contrasts. The purpose of this dissertation is to investigate whether amplitude envelope also co-varies with fundamental frequency in Cantonese, and whether the amplitude envelope cue alone can also aid the perception of lexical tones in Cantonese which uses both tone contour and relative tone height for phonemic tonal contrasts. Signal-correlated noise stimuli were synthesized based on the six Cantonese lexical tones produced naturally in isolation with the carrier syllables /ji/ and /wai/, and contained only the amplitude envelope cue of the six Cantonese lexical tones. The original intensity level of the amplitude envelopes was preserved in one condition of the experiment, but was equalized across tone types in the other condition. Thirty native listeners of Cantonese and thirty native listeners of English were presented pairs of the stimuli, and were instructed to report whether each pair consisted of identical or different Cantonese lexical tones. The results indicated that amplitude envelope co-varied with fundamental frequency in Cantonese. Furthermore, in both conditions of the current Cantonese lexical tone discrimination experiment, the native listeners of Cantonese performed significantly above chance and with greater accuracy and shorter reaction time than the native listeners of English. This suggested that amplitude envelope could cue tone contour and relative tone height for lexical tone perception. Since tone languages in the world are described as using only tone contour, relative tone height, or a combination of both for phonemic tonal contrasts, a theoretical implication of the current study is that amplitude envelope is an additional cue and could cue tone perception in all tone languages. This finding could potentially help improve the encoding of lexical tone contrasts for lexical tone perception in cochlear implant users. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]