As an electronic instrument, these types of accordions are plugged into a PA system or keyboard amplifier to produce sound. Some digital accordions have a small internal speaker and amplifier, so they can be used without a PA system or keyboard amplifier, at least for practicing and small venues like coffeehouses. One benefit of electronic accordions is that they can be practiced with headphones, making them inaudible to other people nearby. On a digital accordion, the volume of the right-hand keyboard and the left-hand buttons can be independently adjusted.