When Locke blew the dog whistle at the end and Boone was like "I think your whistle's broken", Locke retorted something like "You can't hear everything Boone - the sooner you realize that, the better". My gut reaction to that line was that Locke hears the voices (the same voices Sayid heard fleeing Danielle's crib earlier). What say ye?

He may.

He may just be referring to his instinctual knowledge of the island. Recall in Cowboys when he told Boone (or was it Jack) "I can't see it - I can feel it." (paraphrased) when questioned about the how he was picking the trail while searching for Claire.

ETA: His references to the senses are in line with the philosophy of John Locke.

See this thread:
http://www.thefuselage.com/threaded/index.php?topic=4289.0