On my HP computer running Ubuntu 12.04, the brightness and volume increments were much higher than I wanted. On top of that, the notification for the volume was just plain wrong (0% sound did not correspond to 0 on the progress bar). So I decided to override these options with my own commands. I used CompizConfig Settings Manager to add custom commands to the brightness and volume keys (this couldn't be done in the regular settings because these keys were handled by the BIOS, unlike normal function keys). I used xbacklight to control the brightness and amixer to control the volume.

The problem is that the nice notify-send notifications don't show up when I manually set the brightness/volume, so now I have to do that myself too. However, there are two problems with notify-send:

1. The expire time option doesn't work
2. You have to wait until a notification is finished before the next one comes up

Before I overrided the brightness/volume keys, the system was able to send notifications without these two restrictions. Notifications disappeared within 3 seconds (instead of the default 10), and if I double tapped the volume or brightness button, the progress bar would immediately change to the new brightness (instead of showing the old progress bar for 10 seconds and then showing the new one).

Since the system was able to do it, I was wondering how I can achieve the same type of notifications?