Looks like a nice new tool for your bag of tricks -- I have used Algo products on a number of projects over the years, and never had an issue with the product doing what they said it would, or the quality of the solution -
http://www.algosolutions.com/products/audible-and-visual-alerting/2207.html
http://www.algosolutions.com/products/audible-and-visual-alerting/2207.html