How can I play a sound when script execution is ready?

Append any command that plays a sound; this could be as simple as

$ time mycommand; printf '\7'

or as complex as

$ time mycommand && paplay itworked.ogg || paplay bombed.ogg

(Commands assume pulseaudio is installed; substitute your sound player, which will depend on your desktop environment.)

spd-say

sleep 2; spd-say 'get back to work'

Infinite loop with -w if you need extra motivation:

sleep 2; while true; do spd-say -w 'get back to work'; done

Pre-installed on 14.04 via package speech-dispatcher: http://releases.ubuntu.com/trusty/ubuntu-14.04.4-desktop-amd64.manifest for blind people I suppose?

Also add a popup

This combo is a life saver (b stands for beep):

b() ( spd-say 'done'; zenity --info --text "$(date);$(pwd)" & )

and then:

super-slow-command;b

If I'm somewhere in the room, I'll hear it and know that the long job is done.

Otherwise, I'll see the popup when I get back to my computer.

Related: https://stackoverflow.com/questions/7035/how-to-show-a-gui-message-box-from-a-bash-script-in-linux

Just pick a sound on your hard drive, and put a command to play it right after the command you're waiting on; they'll happen sequentially:

$ time python MyScript.py; mplayer ~/ScriptDone.wav

(You can use any player, naturally). I have a script called alertdone that plays a tone and shows an libnotify alert when run; I use it for exactly this occasion:

$ time python MyScript.py; alertdone "Done timing"

It's really simple, so if you want to make your own you can base it on this (mine requires notify-more, mplayer, and ~/tones/alert_1.wav though):

#!/bin/bash
message=${1:-"Finished working"}
notify-more -t 10000 -i /usr/share/icons/gnome/32x32/actions/insert-object.png "Process Finished" "$message"
mplayer ~/tones/alert_1.wav