Again, the reason this works on phone is that you are using the features it already has. A lot of companies are switching over to SIP/VoIP systems for the phone and this provides some control over the computer or to even use the computer microphone/headphone as the conduit for communication..
In this situation, your computer IS a phone, so apps like these would work great to interrupt your music for the phone to ring through and so on..
Otherwise, you are dealing with disjoint systems that don't interact..
As far as coworkers go, no easy solution there short of them knocking loudly or someone attracting your attention as to not frighten you..