Acoustic analysis tests the hypothesis that the physical properties of Pakistani English (PaKE) vowels differ in terms of acoustic measurements of Native American English speakers. The present paper aims to document the physical behavior of English vowels produced by PaKE learners. The major goal of this paper is to measure the production of sound frequencies coupled with vowel duration. The primary aim of this paper is to explore the different frequencies and duration of the vowels involved in articulation of PaKE. English vowels selected for this purpose are: /æ/, /ɛ/, /ɪ/, /ɒ/ and /ə/. Total ten samplings were obtained from the department of computer science at Sindh Madressatul Islam University, Karachi. The study was based on the analysis of 500 (10×5×10=500) voice samples. Five vowel minimal pairs were selected and written in a carrier phrase [I say CVC now]. Ten speakers (5 male & five female) recorded their 500 voice samples using Praat speech processing tool and a high-quality microphone on laptop in a computer laboratory with no background sound. Three parameters were considered for the analysis of PaKE vowels i.e., duration of five vowels, fundamental frequency (F1 and F2). It was hypothesized that the properties of PaKE vowels are different from that of English native speakers. The hypothesis was accepted since the acoustic measurements of PaKE and English Native American speakers’ physical properties of sounds were discovered differently.