Sorry, but I'm not particularly computer literate, so I have to do this step by step. I am getting white sound alternating between the L& R speakers.
dick@library ~ $ aplay -L
default
Playback/recording through the PulseAudio sound server
sysdefault:CARD=Generic
HD-Audio Generic, 92HD73E1X5 Analog
Default Audio Device
front:CARD=Generic,DEV=0
HD-Audio Generic, 92HD73E1X5 Analog
Front speakers
surround40:CARD=Generic,DEV=0
HD-Audio Generic, 92HD73E1X5 Analog
4.0 Surround output to Front and Rear speakers
surround41:CARD=Generic,DEV=0
HD-Audio Generic, 92HD73E1X5 Analog
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=Generic,DEV=0
HD-Audio Generic, 92HD73E1X5 Analog
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=Generic,DEV=0
HD-Audio Generic, 92HD73E1X5 Analog
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=Generic,DEV=0
HD-Audio Generic, 92HD73E1X5 Analog
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=Generic,DEV=0
HD-Audio Generic, 92HD73E1X5 Digital
IEC958 (S/PDIF) Digital Audio Output
dick@library ~ $ speaker-test default -c 2
speaker-test 1.0.27.2
Playback device is default
Stream parameters are 48000Hz, S16_LE, 2 channels
Using 16 octaves of pink noise
Rate set to 48000Hz (requested 48000Hz)
Buffer size range from 96 to 1048576
Period size range from 32 to 349526
Using max buffer size 1048576
Periods = 4
was set period_size = 262144
was set buffer_size = 1048576
0 - Front Left
1 - Front Right
Time per period = 10.954546
0 - Front Left
1 - Front Right
Time per period = 10.953082
0 - Front Left
1 - Front Right
Time per period = 10.953250
0 - Front Left
1 - Front Right