CREATE TABLE table_51345 ("Year" FLOAT, "Award" TEXT, "Category" TEXT, "Type" TEXT, "Title" TEXT)

What award was won in the best sound category for the exorcist before 1998?
SELECT "Award" FROM table_51345 WHERE "Year" < '1998' AND "Type" = 'won' AND "Category" = 'best sound' AND "Title" = 'the exorcist'
SELECT "Award" FROM "table_51345" WHERE "Category" = 'best sound' AND "Title" = 'the exorcist' AND "Type" = 'won' AND "Year" < '1998'