How to making volume stay the same across reboots?

I use headphones with my computer, and when I reboot, the volume gets set to 100%.

Hence, when the logon screen comes up, the drum sound plays through my headphones at maximum volume, which is... well I think you know where I'm going with this...

So, how can I make the volume stay the same across reboots?

I am using Ubuntu 14.04