In a previous role I helped create Noise Maps for Northern England.
The predicted noise levels was done using the IMMI package (which I can recommend) and the cartographic output was done in ArcMap. There are also other packages such as LimaArc which have tighter integration with ArcMap.
I want to take on a personal project to try and create noise maps for large urban areas in Australia. I am interested in both mapping noise from traffic (roads, trams, rail), maybe having a stab at aircraft noise and also looking at how the noise from level crossing bells can be heard by surrounding residents. As its for self development purposes, I have no budget for buying dedicated software like LimaArc or IMMI.
I was wondering if anyone in the GIS-SE community has found a way to create noise maps in a similar approach to how IMMI/LimaArc does?
--EDIT-- I had a play with the noise module for OrbisGIS (user16714 answer and comments below), but had some problems getting it to work - looks like it has a lot of potential but still has to be installed against a beta version and not entirely sure how well it will handle larger datasets. (Will post back if I get further with this).
Ideally I really want to do this all in ArcGIS or a more established open source package (QGIS, GRASS, SAGA, etc.). Have seen some papers that mention tools to do this in ArcGIS, but can't source any scripts/tools as of yet.
Has anyone seen any scripts (Python) or free extensions where this can be achieved directly in ArcGIS?