I thought I was going crazy, but I have this issue too! For me, it's been mainly occurring on teleporting into the Foundation. All will seem to load, and then the client will either:

1) Cease all sound, and the loading circle in the bottom right will freeze for anywhere from 2-15 seconds... and then right itself.
2) Do the above, but not right itself and stay frozen, forcing a hard shutdown of the client.

This has been happening when running the DX11 Client; I've not noticed it happening in DX9, either. Running an Nvidia GTX 970, but with rolled back drivers as - before doing that -I was encountering the random crash errors that seem to have been plaguing many running DX11.