how can I get a beep sound when GRUB appears

[Milton]

Hi,

A question for a TERRA MOBILE 1712 dual boot with Ubuntu 14.04 and Orca 
3.16.2.
I would like to enable a beep sound when GRUB appears. So I did in a 
terminal:
sudo gedit /etc/default/grub
and I notice the line:
# Uncomment to get a beep at grub start

#GRUB_INIT_TUNE="480 440 1"

So I did uncomment the line and ran update-grub.
But still no beep. Do I miss something? Thanks.
Milton