[eng] The Covid-19 Pandemic has forced society to change several habits and adopt health measures that have affected our daily lives. In the educational system, the obligation of masks in the class environment has affected teaching methodologies. This paper aims at analysing the effects of wearing a mask in the field of English as a Foreign Language. An experiment to a reduced group of secondary school students has been conducted to prove the effects masks have on auditory and articulatory perception. With the participation of ten students, the paper demonstrates that they experienced slight difficulties in the perception of minimal pairs containing the voiced bilabial plosive /b/ and the voiced labiodental fricative /v/ when they were uttered in a mask condition. Furthermore, the paper provides an overview of the previous literature that deals with speech perception and concludes with an approach of the implications the experiment has in the communicative aspect of secondary education.