Similarly, I use radio files, as near to the date as possible.
A good source, that I've posted in a separate thread recently is
Joeri's radio files, she has some outstanding stuff there. And as Gustav says, a tinny, lo-fi speaker for an MP3 player or similar is great - remember to turn it off when going silent though
I was the one that invested in the surround sound and sub-woofer and recommended it to Gustav. As SH3 doesn't support proper surround sound, I got hold of a pretty old one with a "matrix" system that converts 2 speaker output to surround sound - and it actually works really well.
Other things you can do is use real stop watches, maps and things like that can be good too. Recently I converted a set of 1930s headphones, as close as I could find to the Neufeldt & Kuhnke radio / hydrophone headset styles, so that they worked with the PC. So now I can sit at the hydrophones for hours on end, one ear uncovered so I can listen for orders, and sit whispering contact updates to an empty room... There's some that say you can take immersion
too far. Obviously, those people are crazy.
The Almost N&K Headset
Here's the headset in question. It still needs a bit of a polish, just so it doesn't look too worn, these things would have been new in the 30s/40s after all... I also need to cover the wire with braided fabric (dark brown). The plan had been to use a hollow shoe lace, but need to readjust that slightly.
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