Louis Armstrong, a jazz trumpeter and singer, blows across the top of two pipes of equal length and equal diameters in such a way that he produces a loud sound at the fundamental mode of each pipe. Both pipes are open at the top end, however, one pipe is open at its bottom end as well, while the other pipe is closed. Which pipe produces the higher pitched sound? The pipe that is closed at the bottom produces the higher pitched sound. Neither. Both pipes produce the same pitched sound. There is not enough information to determine. The pipe that is open at the bottom produces the higher pitched sound