Enabling hardware button sounds reveal key repeats
28 May 2015
Under Start > Settings > Sounds & Notifications > Sounds tab, the "Hardware buttons" checkbox is unchecked by default intentionally because the Home key outputs more than one key code in series, as well as the modifier keys (Shift, Ctrl, Alt, 2nd, etc.) were chosen to be "sticky" by repeating until the key to be modified has then been pressed (or the modifier key has been pressed again to stop repeating while waiting for another key to modify). This is to accommodate single hand/finger/thumb operation. Having hardware button sounds enabled makes this behavior seem like a mistake instead of intentional (by design), so it is recommended to keep hardware button sounds disabled.
If you would prefer modifier keys not to be sticky, it may be technically possible to change this behavior. But it may be more work then it is worth. If you would like to discuss this possibility, please contact firstname.lastname@example.org. Some information may also be provided in the "A2-Keyboard-Power-User-Guide.pdf" included in the SDK at this web page.