Dear Jobsu84,
What is the nature of your industry? How many employees work on the floor? What is their qualification and what is their designation in general? What is the cause of noise? Against the backdrop of the humming sound of machines, are employees required to talk loudly or even shout?
What technological means you can adopt to avoid oral communication amongst the employees? If not technological means then can introduce whiteboards where someone can update the required information constantly?
Yes, maintaining silence at the workplace is important. Noise is a distraction for others. However, you may call meeting of all the employees and take their views on how to improve silence at the workplace. Rather than issuing notice, if you involve them, it will have a better impact. After the meeting, prepare minutes of the meeting and circulate among all the employees. It can be said as code of conduct.
Thanks,
Dinesh Divekar