The current study aims to evaluate the perception of English high-front vowels, low vowels, and high-back vowels by Kichwa-Spanish bilingual speakers and Ecuadorian Spanish speakers. The study was carried out in Ambato, Ecuador, with 24 Kichwa-Spanish bilinguals and 24 native monolingual speakers of Spanish who were university students from Universidad Técnica de Ambato. The aim was to determine the influence of their linguistic backgrounds on English vowel perception. The investigation responds to two main questions 1) How do perceived phonetic differences between an English sound and its closest L1 counterpart influence the perception of English sounds in bilingual Kichwa-Spanish and monolingual Ecuadorian Spanish learners of English? and 2) To what extent can bilingual Kichwa-Spanish and monolingual Ecuadorian Spanish learners of English distinguish phonetic variations between English sounds and their closest L1 equivalents? The data was gathered by exposing participants to AX and ABX tasks on E-Prime 2.0 software. Results from the ABX task indicate that bilingualism did not significantly impact participants' ability to recognize English vowels. However, findings from the AX task suggest that linguistic background may influence sound discrimination in this task.