French learners at university meet difficulties in the comprehension of oral English. Being in a formal context of language learning, they need to develop language awareness to compensate for insufficient exposure to the English language. To meet the students' needs, data was collected in order to pinpoint the main errors made by French learners in listening tasks. The errors were then analyzed and put into perspective with the system of oral English; a connection clearly appeared between the errors and what is barely heard or cannot be heard in reference to written English, hinting at what could cause poor oral comprehension. Three areas of knowledge appeared to be missing in the students' background: the links between morpho-syntax and phonology, the mastery of phonological data found in dictionaries and the possible recourse to strategies in order to compensate for what has not been heard properly. These issues were addressed in an on-line program designed for non-beginners of English at university. This paper deals with the assessment of the progress made by users of the program in a formal learning situation. Two groups of learners were considered: students whose major is English, and students for whom the study of English is optional. Two series of tests were implemented, before and after the use of the program. The tests focused on the ability of learners to read IPA transcription, to count syllables in oral English, and to pronounce auxiliaries and prepositions in different contexts. The results to be discussed establish that the two groups of learners significantly improved their knowledge of oral English. Of particular interest is the fact that, even if the two groups had significantly different knowledge of oral English before using the program, with non-specialists of English having poorer knowledge, the two groups obtain similar results on the post-test, showing greater progress on the part of the non-specialists. All learners appear to improve dramatically their knowledge of IPA and their ability to use it. The progress measured by the tests was corroborated by other modes of assessment: a survey on the students' judgment as regards the usefulness of the program, and individual interviews focusing on what the students recall from the content of the program. In the latter, the students used relevant meta-linguistic and meta-cognitive expressions, showing their ability for further progress in developing listening abilities in English as a Second Language (ESL).