In the Meymandi dialect of Persian, guttural consonants (/χ, ʔ, h/) have a shared effect on the preceding short vowels /a/ and /o/. The goal of this chapter is to explore this process from both phonological and acoustic viewpoints. Assuming that Meymandi is a language variety where gutturals are tongue root articulated, they are classified under the pharyngeal natural class. Following previous studies which have shown that the [RTR] feature leads to F1 raising and F2 lowering in adjacent vowels through pharyngealization harmony (PH), we argued that the spreading of the [RTR] feature of gutturals causes preceding /a/ and /o/ to undergo PH. We collected data from eight native Meymandi speakers using controlled stimuli in the form of short dialogues and acoustically analyzed the recorded data using Praat. Then, Welch two-samples t-tests were implemented to compare F1 and F2 of vowels in three conditions. The result of the statistical analyses showed that the first two formant frequencies of /o/ preceding pharyngeals is significantly higher than those of /o/ followed by other consonants. However, the difference between the two formant frequencies is not significant considering the vowel /o/ preceding pharyngeals vs. the vowel undergoing PH. Similarly, the first two formants of vowels undergoing PH are not significantly different compared to those of /ɑ/. It can be deduced from these comparisons that the /o/ preceding pharyngeals is articulated closer to the vowel resulting from PH, rather than the /o/ preceding other consonants. Our study showed that, phonologically speaking, under the effect of the [RTR] feature spreading, the place of articulation of /o/ shifts toward that of /ɑ/. The acoustic evidence suggested that here the [RTR] feature raises the preceding vowel’s F1 and F2, contradicting the expectation about lowering of F2, which is due to the more inherent front articulation of /ɑ/ compared with /o/.