Also, are there any mods that improve the sound/speech? I can't remember if it was vanilla or modded but I would have to be looking right at someone to hear them. If I turned away or to the side it would sound like they were miles away.
that actually seems more like a surround sound error than anything else. Skyrim is full of sound bugs that I have yet to find a reliable fix for - the one you mentioned above is one of them, but can also include full on static sound if you don't have things (on your system) setup properly.
Try the following:
1: open the sound control panel, and find your default speakers (will have a green check next to the icon). Click on the Properties button.
2: from here, go to Enhancements tab. You should have at least 4 options, Bass Boost, Virtual Sound, Room Correction, and Loudness Equalization. Virtual Stereo can help fix the problem, but ONLY if you are NOT using a 5.1 surround sound system (ie: a headset or a 2.1 stereo system) The other options can help tailor the sound how you want it - you should try each of them on and off to find what you like anyway.
3: from there, go to the Advanced tab. There should be a pulldown menu with various options of bit & Hz quality. This is where most forum posts on google suggest 16bit and 44100 Hz (CD Quality). To be honest though, you'll probably want to see if any other qualities can help fix the issue. 16 bit, 44100 Hz is what I use, though I tend to get fewer audio glitches at 48000 Hz. Note that the quality here CAN be influenced by what output method you're using (as in, my USB headset has more/higher quality options than my basic "plug in the back" studio headphones).
If you are using any software to go with your sound card, you'll want to find the same/similar options in it's control panel//configuration to match whatever you set in the Windows Sound control panel. Such as in Realtek control panel, you'd want to find the Virtual Surround check box.
If you ARE using a 5.1 surround sound system, you'll want to still give the above some consideration. You'll also want to make sure each of your speakers is actually functional (the basic windows "test" option will suffice, and your surround sound system or your control panel for it should also have a test option). And yes, I know it sounds stupid, but you'll want to verify they work, and are configured properly. Found a good handful of posts via google of people who, through Skyrim, learned at least one of their speakers was dead.
The Sun was born, so it shall die. As we were forged we shall return. I know in darkness I will find you, giving up inside like me.