The character you entered is just another Unicode character outside the range that the MATLAB command prompt (and possibly even the editor) knows how to display. Just because it represents the "symbol for bel" doesn't mean it has any special significance or would play a sound when entered (no more than other musical symbols like: ♩
or 🎻
)
Of course you can always have it saved in a regular string and display it in a GUI window:
% The default on Windows is 'windows-1252'
feature('DefaultCharacterSet','UTF-8')
c = char(9223);
uicontrol('style','text', 'units','normalized', 'position',[0 0 1 1], ...
'string',['char = ' c], 'FontName','Arial Unicode MS', 'FontSize',72)
or even get its encoding in say UTF-8:
>> cellstr(dec2hex(unicode2native(c,'UTF-8')))
ans =
'E2'
'90'
'87'