No "Problem Reporting" files attached.
Read FAQ, "Problem Reporting" again. Carefully. Attach all requested files/output.
https://www.tonymacx86.com/threads/faq-read-first-laptop-frequent-questions.164990/
Use the gen_debug.sh tool mentioned in the FAQ, that way it is less likely you'll omit something.
Sorry for the delay in responding. The reason was because I decided to upgrade to 10.13.4 before fixing the audio and that seems to have fixed the audio by itself. I didn't have to deal with AppleHDA any longer. It magically started working after the update.
I have an old problem (which was present even before updating to 10.13 series) with this laptop's touchpad. VoodooPS2Controller.kext loads correctly and I have mouse and keyboard working fine, but the touchpad's only multitouch feature that works is the double tap to right click. Additionally if I do a left click using the touchpad lower left portion, it seems to click multiple times on MacOS, like 5 or 6 times (the same problem doesn't happen on Windows, so I'm guessing it may not be a hardware fault). It is a Synaptics, but Dell does not provide any drivers (even for Windows) for this touchpad. I will attach the required error reporting files in a moment. As usual, many thanks for your time and help.
Update: The multiple clicks seem to have been fixed using the latest VoodooPS2Controller version (which I had just installed right before pulling the debug files). I also had the problem of the touchpad and keyboard not working after a fresh reboot or sleep, so I am testing to see if it's gone as well. But the multitouch problem I mentioned still persists.