We have a business in a large, old, noisy building and have no loud speakers in the plant. We have the need to find our maintenance man and/or plant manager on a daily basis. Would a cell phone or pager be better for them to carry. It is a noisy environment with a lot of equipment running so a vibrator would be a must. Which would have a stronger signal?? Which would be less expensive to have?

Thanking you in advance for any suggestions you can offer...