구문 해석 부탁드려요

1) The disadvantage in working underwater is that it is almost impossible to tell which direction any sound comes from.
which 뒤부터 자연스럽게 해석이 안 돼요. 문장 전체 해석 부탁드립니다.
2) The difficulty in underwater hearing comes, surprisingly, from the ease with which a sound travels through water.