Peopleware is a really amazing book. IMHO it isn’t just for managers or management people, but to the all people engaged in collaboration. So please consider to read it since I’m sure it will provide a lot of joy for you!

Some great quotation.

• The manager's function is not to make people work, but to make it possible for people to work.
• There are a million ways to lose a work day, but not even a single way to get one back.
• Quality—If Time Permits

Among other things book states that productivity heavily depends on the working environment. The main negative factor is Interruptions and Noise. So companies should stop saving money on the office space. Since in that case they will pay hidden cost on the productivity drop. So it’s much better to provide nice (required?) working environment to the employees to make them happy and receive productivity boost.

As about Signal & Noise issue. The authors stated that Phone (I’m sure it’s related to the Skype calls as well) usage should be avoided in the most cases. If you really need an immediate answer to continue your work, then phone should be your choice. In other case they recommend to use e-mail. All we need to be able to rely on e-mail is just to come to the agreement that e-mail will be checked with reasonable frequency.

People must  learn  that it's  okay sometimes not to answer their phones, and they just learn that their time—not just the quantity but its quality—is important.