When my professional input on a project is not heard due to communication gap with co-engineers, what should i do to improve productivity expertise?

As your professional inputs are not heard due to communication gap, simply you should work on 'communication gap'.

It will solve a bundle of issues.

The only way to improve productivity is to deliver error free outcomes consuming far less time than expected. As 'Rome was not built in a day', so is this expertise also. Should be practiced and most of all should know the tackle any issues that comes. Its better to practice and take advice from senior experts till we are ourselves and expert.