The study examines two dialects of the Igbo language, namely Aro and Mgbo, and analyses the acoustic structure of its obstruents as spoken by native speakers. This study sets out to, among other things, identify the obstruents which occur in the dialects, characterise these obstruents, analyse the acoustic properties, and find out the manner of relatedness of the obstruents in the two dialects. Four adult respondents (two for each dialect) aged between 60-80 years who are native speakers of the dialects were randomly selected. The data were recorded electronically using a high precision Sony ICD-UX560 recorder and transferred into the computer via Praat speech analyzer software. The data analysis was carried out with the SIL Speech Analyzer version 3.0.1 (1996-2007) and Praat. These were used in transcribing recorded tokens, cutting portions of tokens and analyzing the data. The measurement of the pitch, intensity and duration reveal some significant differences within the two dialects. In most Northern Igbo (Waawa) dialects, back rounded vowels are weakened as is evinced in [nɣɔkə] and [ŋkɔ]. Although the vowels are evident in the syllable structure, the final vowels are so weak that they are not phonetically interpretable.