Here is actual recorded audio (with no loss of quality,) from a conversation I had with Van Stuber who lives near a military base.
Can you explain the weird ping beepish noises?
The file can be downloaded (mp3) here:
http://www.ubstudios.com/audio/scaryphone.mp3
The file has been edited to include only the parts when the noises appeared, which was failry often. This is only a sniplet of them as I was not recording the whole time.
Van can confirm this conversation as authentic.