Which of the following statements about hearing and sound are true?1. Low frequency waves are perceived as low pitched waves2. High frequency waves are perceived as high pitched waves3. Low frequency waves are perceived as high pitched waves4. High frequency waves are perceived as low pitched waves5. The human ear can always hear the same frequencies, independent of age6. Wave energy is amplified by the smaller oval window1, 2, 5, and 61, 2, and 63, 4, 5, and 63, 4, and 6