worldizing is probably your best bet. transmit the audio through some hand-held CB's and record the output. Also, the type of sound will depend on the 'fake' modulation - FM will sound different from AM, SSB etc.
MP3s often save with some padding, a small period of silence at the head or tail.
Maybe try something like MpTrim to remove it.
See https://hydrogenaud.io/index.php?topic=78306.0 for some discussion on the topic.
If you first imagine that sound waves emanating from a point source (which you are going to have to approximate as a speaker) will emit spherically. Where the sphere intersects first with the paper, you will notice a dot on the paper appearing in your image. That is the point at which the wavefront hits the paper and is the earliest ...
There are no standards as such for Sound Effects libraries. There are related standards around file data formats maintained by the AES but generally there is nothing required that is related to Sound Effects libraries specifically.
There are industry conventions that you might consider, such as:
Recording at a minimum of 48kHz sampling rate (preferably ...