The reciprocal influences between the human being and the ecology are inseparable. If any change occurs in the surroundings, man as individual, as well as the whole society of which he forms part, tries to accommodate and cope with these changes in order to face the environmental challenges. Linguistics reflects the aforesaid changes in response to geographical features. This paper aims to determine the linguistic features (at the phonological level) of the people who live in mountainous areas as opposed to those who live on the plains / in coastal areas. It also aims to determine the impact of tough and harsh geography, on the one hand, and simple and plain geography, on the other, on linguistic variation. Every group of people that lives in a specific geographical area is characterized by unique linguistic forms that reflect the physical geographical features of the piece of land they live on. This natural balance between man’s activities and his ecology prompted the researcher to study the topographical changes and their impact on linguistic variation in an eco-linguistic study into Yemeni Arabic. The researcher collected as much data as possible from the residents of both areas in order to make a comparative ecological linguistic study to verify the underlying hypothesis in this study.