Praise be to Allah.
With regard to whether this is enough for them, there is no doubt that this is good enough if they cannot go and be with the scholars. It makes up for not being able to be with the people of knowledge, although being with them is preferable and makes it easier to understand and discuss matters. But if they cannot do that, then listening to tapes is enough, because this is all they can do.
Can they be regarded as students or seekers of knowledge when they are limiting themselves to that? We say, yes they can, if they make a great effort, just as a person can become a scholar if he takes knowledge from books. But the difference between taking knowledge from books and tapes and receiving it directly from the scholars is that it is much better to take it directly from the scholars, because then it is easy to discuss things, unlike when listening to tapes or reading books. It requires a great deal of effort to learn all aspects of knowledge in this way. (By the same token, learning directly from scholars means that one is less likely to misunderstand things than when one learns from tapes and books).