Oral/Aural

One of the basic requirements of language is to differentiate concepts, especially things which may be confusable. So why is it that for many speakers of English (including me) oral and aural are pronounced exactly the same (i.e. they are homophones)? If I tell you that we have an /ɔ:rəl/ exam tomorrow, you have no way of telling whether it is a listening (aural) test or a speaking (oral) test.

John Wells's Longman Pronunciation Dictionary (2008, p. 57) tells me that aural can be pronounced as /aʊrəl/ in order to differentiate it from oral; but the fact remains that it usually is not.