Use a namespace for the variables

[aero31aero]

Variable names like SOUND etc are quite common to be accidentally set up/conflict with some other tools. Recommend prefixing with NOTIFY_ for ease.

Example: NOTIFY_SOUND, NOTIFY_MIN_INTERVAL etc.

[kaustubhhiware]

From what I understand, you suggest it should be possible to change these attributes without editing the script ?

If that is the case, then prefixing NOTIFY_ makes perfect sense.
Now, to achieve this, another approach could be
notifyre --set min_interval 10 or something similar.

[aero31aero]

Since we are sourcing the scripts and those variables are declared globally in the script, they are now in the global namespace.

Steps to reproduce:

$ cd /path/to/git/repo
$ source ./notifyre.sh
$ sleep 2 # no notification as expected
$ export MIN_INTERVAL=1
$ sleep 2 # notification gets generated