Also run alsamixer from a terminal window and see if the mute is turned on for the device you are trying to play to.
I've seen this one before, not sure why the device was muted by default.
Following a couple of brutally busy months I finally found time to review and reply to those who kindly offered to help.
I've been unable to relocate links to the postings mentioned earlier. It seems as though the postings are no longer available.
I ran alsamixer as bob suggested. It lists an Intel HDMI/DP LPE Audio card. No chipset is identified. Only a few of the Function keys work; F2 and F6. The F3, F4, F5 keys do not seem to be working as no options are presented when they are pressed; no additional settings are made available. Pressing F1 opens the Help dialogue, F2 opens a System Information window and F6 allows selection of a sound card; the one mentioned above is default. A message indicates the sound device does not have any controls.
Linux Sound Settings indicate two devices are available;
Multichannel Output - Atom/Celeron/Pentium Processor x%-E8000/J3xxx/N3xxx Series PCI Configuration Registers and;
Analog Output - Atom/Celeron/Pentium Processor x%-E8000/J3xxx/N3xxx Series PCI Configuration Registers
Although I have tried both Analog and Multichannel, Multichannel is currently set as the profile. A speaker test from the Sound Settings panel reveals no output, or at least there's no sound from the Pioneer AV VSX-531 the the device is connected to.
I believe the problem is related to configuration of the kangaroo PC as this same device worked in the same port on the Pioneer prior to switching to Linux.
Any thoughts on this issue would be greatly appreciated.