This study suggests revisions to the segmental and tonal phonology of Kabiye following a reanalysis of consonants, vowels, and tones in the speech of 7 male native speakers. Acoustic investigations are also included to illustrate some phonetic aspects of segments and tone. Data were elicited through three speech styles--wordlists, short phrases, and storytelling--later transcribed and analyzed. Revisions are made to the phonetic and phonemic inventories of consonants and vowels, as well as to the inventories of the underlying tonal melodies on noun roots, verb roots, and noun suffixes, as indicated by the results of the current study, which combines a more adequate methodology with newer phonological theories. In Kabiye, the surfacing of obstruents' underlying voicing specifications is known to be restricted in both initial positions where they are all realized as voiceless and in medial positions--in the simple root and after a morpheme boundary--where they have a tendency to surface as voiced. Under the current study, it is further found that contrasts in voiced and voiceless obstruents are nonetheless kept in medial positions, but they are regulated by morphology. In medial position, there are voicing environments, which voice all the obstruents occurring after a morpheme boundary, but the underlying voicing specifications of obstruents also surface after a morpheme boundary in certain contexts, which are voicing-neutral environments. In the latter environments, the current study found voiced and voiceless obstruents occurring in contrastive pairs, with the exception of the obstruents in the bilabial and the retroflex subclasses. Consequently, these subclasses revealed themselves as defective, with only voiced phonemes. The analysis of nasals determined a nasal archiphoneme, which is now part of the phonemic system. The vocalic system is also found to include a vocalic archiphoneme, unlike in any of the previous studies. This underspecified vocalic segment, determined to be from consonantal origin, is the element underlying the vowels known previously as "pharyngealized" or "velarized" vowels, and replaces the unattested segment "/[voiced velar fricative]/" that appeared in previous studies. Tone analysis determined four lexical tonal melodies on five groups of noun roots--one of which includes toneless roots--and five lexical tonal melodies on five groups of verbs roots, also leading to a revision of the tone classes of nouns and verbs. In addition to the various revisions, which affect the analyses of segments and tone at the phonetic and the phonological levels, basic acoustic illustrations have been included at various points in the current study to back up some phonological claims and to show the physical nature of pitch as the correlate of tone. [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.]