How to fix "choppy" sound on Asterisk on a VMWare virtual machine

Testing the speaking clock application (*60) on Elastix 1.3, the sound is "choppy" and compressed (as if spoken in a hurry).

Steps taken to try to mitigate the problem:

uname -r --> 2.6.18-53.1.19.el5
wget http://dev.centos.org/~tru/kernel-vm/5/RPMS/i386/kernel-vm-2.6.18-53.1.1...
wget http://dev.centos.org/~tru/kernel-vm/5/RPMS/i386/kernel-vm-devel-2.6.18-...
rpm -ivh kernel-vm*.rpm

Edit /etc/grub.conf and make the default kernel the -vm one.
Reboot.

wget http://downloads.digium.com/pub/zaptel/zaptel-1.4.12.1.tar.gz
tar xzvf zaptel-1.4.12.1.tar.gz
cd zaptel-1.4.12.1
./configure
make && make install
make config
genzaptelconf
reboot

Edit /etc/grub.conf, adding to the end of the 'kernel' line:
clock=pit
(other suggestions were: acpi=off noapic nolapic nosmp; however, it worked fine without them)
reboot

Install VMWare Tools:
On the VMWare server console, select Install VMWare Tools
mkdir /media/cdrom
mount /dev/hdc /media/cdrom
rpm -ivh /media/cdrom/VMwareTools-1.0.7-108231.i386.rpm
vmware-config-tools.pl

Edit in the .vmx file:
tools.syncTime = "TRUE"