Seeing the faults in "If You Could See What I Hear," the film-biography of blind singer Tom Sullivan, is easy. The story line is disjointedly episodic, the hero is poster-child perfect, and the dialogue never strays from the subject of blindness.

But it is easy to overlook these drawbacks, because this movie is unusually funny, scary and thoughtful. If the word "heartwarming" hadn't come to suggest patronizing pity when applied to the achievements of disabled people, it would be appropriate here.

What warms the heart is not any treacly triumph over blindness, but a tart determination to work with it. To a girl friend who remarks that Sullivan doesn't seem blind at first acquaintance, he replies with devastating sarcasm, "Isn't that wonderful!"

And although his variety of achievements is dazzling -- a doctoral candidate at Harvard, he is a singer and composer who skydives and wins at darts, golf, and wrestling in his spare time, when he isn't making love to beautiful young women -- there is no suggestion that he has "overcome" such disadvantages as needing to be warned when there is a step or a park bench in his path.

It is, in fact, one of the tremendous accomplishments of this film that the resulting pratfalls come off as funny. So does the conventional tactlessness of others, as when he is solemnly asked, "Was it an accident?" and replies, "Well, it wasn't on purpose."

Marc Singer does a clever job with the title role, but the atmosphere is even more deftly established by the skills of Shari Belafonte Harper and R.H. Thomson, in the unsentimental roles of girl friend and roommate.

She rejects Sullivan's marriage proposal, admitting she's not willing to spend her life "babysitting a blind man;" and he does not add the burden of self-sacrifice to his good- natured helpfulness. Although a devoted friend, he fights back: "You make fun of sighted people, and I'm likely to go through your closet and mix your checks and your stripes." And he has no qualms about going on with his own life: "Time to think about a new guide dog -- I'm off tomorrow."

The shocker of the film is a scene in which Sullivan, casually asked to keep an eye on his fiancee's baby sister, frantically combs the swimming pool in which he realizes the child is drowning within his reach. What makes this scene almost unbearable is not only the obvious tragedy, but the realization that no amount of understanding would be able to remove the attachment of blame to him in the event of the baby's death.

All this is quite an emotional workout, hardly leaving the viewer with spare energy to wonder why the hero can't once in a while lose a game, like everyone else, or engage in a conversation unrelated to his blindness. IF YOU COULD SEE WHAT I HEAR -- At the AMC Academy, NTI Buckingham, NTI Landover Mall, NTI White Flint and Springfield Mall.