Usually you see computers and what not get 'upgrades' from their standard production models every few months or so. More memory, software, etc etc. Basically it is going to go through 'Trial and Error' you have this device out for use. So, naturally performance will be taken into account.
Once it is in use they'll be finding ways to improve it from hardware, to software, faster processing of the languages, and replies, etc etc. So it is safe to say little tweaks, and mods will happen anywhere from a mere week, to months at a time. Usually from improving on your present platform, and then working towards something more along the lines of the Earbud as inspiration, technological developments advance as well as your people seeing where they want this thing to go and what they want out of it. You're basically tempering a blade here, it would naturally start out as a hot glowing piece of steel (The Edel) and with use (Hammering it out) you're shaping it into a blade. Once everything is said and done, it'll be a much different machine.