Not all mechanical keyboards are loud. Some people like an audible click with each key, and so will buy a keyboard with a switch like the Cherry MX Blue[1]. Some don't, or work around other people and are considerate, and choose a Cherry Red or Brown, or equivalent from other manufacturers. (Red has a very linear feel, while brown has a sort of a 'bump' when it activates, similar to the ones that click, but not as extreme and without the noise.) These don't make much sound at all, unless you hit the key hard enough that the actual plastic key cap bottoms out. That can easily be solved though, either by typing more gently and not bottoming out (which will allow you to type faster and with less stress on your fingers) or by putting O-Ring dampeners around the keys[2].

[1] http://www.pcworld.com/article/242037/mechanical_keyboard_fa... [2] http://www.wasdkeyboards.com/index.php/products/keyboard-acc...

I use a Leopold FC750R with brown mx cherry switches[0] at work. It uses a sound dampening pad and is no louder than a regular membrane keyboard. My coworkers were hesitant about me using a mech at the office when I first got hired but now have no complaints after realizing not all switches and keyboards sound like a type writer. Btw I absolutely love that keyboard and Leopolds in general, I have 3 of them... Bottom line is some mech keyboards are extremely loud, especially if you bottom out on every key press, but there are many options for noise reduction; use brown switches, use a keyboard with a dampening pad, install o-rings on each switch, don't bottom out.

[0] https://mechanicalkeyboards.com/shop/index.php?l=product_det...

I haven't had any complaints from my fellow coworkers in the past six years I've been working at The Company (I brought in a True-Blue IBM Modem M keyboard to work (six years ago, still using the same one)---I have about half a dozen in storage just in case). Sturdy construction and they keep on working.

More important---no Carpal Tunnel Syndrome.