Possible Clues:

• The heart a listener will have?
• Canal locale
• The body's balance regulator
• Labyrinth in which you'll find vestibule
• Labyrinth
• Hidden part of the body revealed by Pearl
• Site of the smallest canal I can think of
• Bony labyrinth
• Where the semicircular canals are to be found
• Serves drink, poetically speaking, before artist returns by canal system