Front mid-vowel phonemes /e/ and /ɛ/ are contrastive in Gallego, while Spanish contains the phoneme /e/ and English contains the phoneme /ɛ/. This study investigates how Language Mode, Language Dominance, and L3 proficiency in Spanish-Gallego early bilinguals affect front mid-vowel production in L3 English. Language Mode (Grosjean 1985) represents the real-time activation of a speaker’s languages and the associated processing frameworks, heavily influenced by environmental and psychosocial factors. We manipulate participants' Language Modes using story-retelling and sentence-reading tasks across their languages. The resulting Euclidean distances between vowel tokens will be measured and analyzed against Bilingual Language Profile (Birdsong, Gerken, and Amengual 2012) Language Dominance ratings and self-reported English proficiency. We expect to find that participants with higher proficiency in English will have greater distinction between /e/ and /ɛ/ phonemes across all three languages, that stronger Language Dominance of Gallego over Spanish will correlate with greater distinction between these phonemes, and that activation of Gallego or English Language Mode will also correlate with a greater distinction on average for speakers. We anticipate that participants with low self-reported English proficiency will see greater distinction between these phonemes in the Gallego Language Mode conditions, but not within English Language Mode, following Escudero's (2005) Second Language Linguistic Perception model and it's extension to phonological production as proposed by Casillas and Simonet (2018).