no audio on boot and stuttering afterwards

[Fibonacci]

Right after boot I have no audio on my machine until I run pulseaudio -k. Then I have normal audio for a very short time (a few seconds) until it begins stuttering. The stuttering gets progressively worse with time, and re-running pulseaudio -k DOESN'T solve it. Sometimes it disappears by itself for a few minutes only to restart as described later.
While trying to play audio, I get many of the following two messages in /var/log/syslog, both when I have no audio and when I get stuttering:

Nov 16 23:04:45 prower-desktop rtkit-daemon[14282]: Successfully made thread 20064 of process 4156 (n/a) owned by '1000' RT at priority 5.
Nov 16 23:04:45 prower-desktop rtkit-daemon[14282]: Supervising 1 threads of 1 processes of 1 users.

Nov 16 23:04:48 prower-desktop rtkit-daemon[14282]: Warning: Reached burst limit for user '1000', denying request.
Nov 16 23:04:48 prower-desktop rtkit-daemon[14282]: Supervising 0 threads of 0 processes of 1 users.

The process number mentioned in the first message is invariably /usr/bin/pulseaudio --start --log-target=syslog.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: pulseaudio 1:8.0-0ubuntu3
ProcVersionSignature: Ubuntu 4.4.0-47.68-generic 4.4.24
Uname: Linux 4.4.0-47-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CurrentDesktop: KDE
Date: Thu Nov 17 23:35:55 2016
EcryptfsInUse: Yes
InstallationDate: Installed on 2016-04-27 (204 days ago)
InstallationMedia: Kubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
SourcePackage: pulseaudio
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/04/2012
dmi.bios.vendor: Intel Corp.
dmi.bios.version: BLH6710H.86A.0160.2012.1204.1156
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: DH67BL
dmi.board.vendor: Intel Corporation
dmi.board.version: AAG10189-206
dmi.chassis.type: 3
dmi.modalias: dmi:bvnIntelCorp.:bvrBLH6710H.86A.0160.2012.1204.1156:bd12/04/2012:svn:pn:pvr:rvnIntelCorporation:rnDH67BL:rvrAAG10189-206:cvn:ct3:cvr: