UbuntuTips/Hardware/SoundTroubleshootingを参照しながら、調査した結果情報です。

下記の結果から、問題は特定出来ないようでう。なぜ、GNOMEデスクトップ環境の「サウンドの設定」
で、サウンドの出力先を[SB0400 Audigy2 Value]選択した場合に音が出ないのか判りません。
該当カードのデバイスドライバーを更新する必要があるのでしょうが？
何方か何かお気づきと点が御座いましたら、サポートを宜しくお願いします。
 
１．サウンドデバイスがPCに認識されているかの確認
$ lspci | egrep -i multimedia\|audio
00:1f.5 Multimedia audio controller: Intel Corporation 82801EB/ER (ICH5/ICH5R) AC'97 Audio Controller (rev 02)
02:0d.0 Multimedia audio controller: Creative Labs SB0400 Audigy2 Value

２．ALSAレベルでサウンドデバイスが認識されているかの確認
$ cat /proc/asound/cards
0 [ICH5           ]: ICH4 - Intel ICH5
                      Intel ICH5 with AD1985 at irq 17
1 [Audigy2        ]: Audigy2 - SB Audigy 4 [SB0610]
                      SB Audigy 4 [SB0610] (rev.0, serial:0x10211102) at 0xe000, irq 21

$ cat /proc/asound/modules
0 snd_intel8x0
1 snd_emu10k1
                     
$ cat /proc/asound/card0/codec*  | grep -i codec
cat: /proc/asound/card0/codec97#0: ディレクトリです

$ cat /proc/asound/card0/codec97#0/* | head -n1
0-0/0: Analog Devices AD1985

３．PulseAudioを使う設定になっているか確認
$ aplay -L
default
    Playback/recording through the PulseAudio sound server
null
    Discard all samples (playback) or generate zero samples (capture)
pulse
    PulseAudio Sound Server
sysdefault:CARD=ICH5
    Intel ICH5, Intel ICH5
    Default Audio Device
front:CARD=ICH5,DEV=0
    Intel ICH5, Intel ICH5
    Front speakers
surround21:CARD=ICH5,DEV=0
    Intel ICH5, Intel ICH5
    2.1 Surround output to Front and Subwoofer speakers
surround40:CARD=ICH5,DEV=0
    Intel ICH5, Intel ICH5
    4.0 Surround output to Front and Rear speakers
surround41:CARD=ICH5,DEV=0
    Intel ICH5, Intel ICH5
    4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=ICH5,DEV=0
    Intel ICH5, Intel ICH5
    5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=ICH5,DEV=0
    Intel ICH5, Intel ICH5
    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
iec958:CARD=ICH5,DEV=0
    Intel ICH5, Intel ICH5 - IEC958
    IEC958 (S/PDIF) Digital Audio Output
dmix:CARD=ICH5,DEV=0
    Intel ICH5, Intel ICH5
    Direct sample mixing device
dmix:CARD=ICH5,DEV=4
    Intel ICH5, Intel ICH5 - IEC958
    Direct sample mixing device
dsnoop:CARD=ICH5,DEV=0
    Intel ICH5, Intel ICH5
    Direct sample snooping device
dsnoop:CARD=ICH5,DEV=4
    Intel ICH5, Intel ICH5 - IEC958
    Direct sample snooping device
hw:CARD=ICH5,DEV=0
    Intel ICH5, Intel ICH5
    Direct hardware device without any conversions
hw:CARD=ICH5,DEV=4
    Intel ICH5, Intel ICH5 - IEC958
    Direct hardware device without any conversions
plughw:CARD=ICH5,DEV=0
    Intel ICH5, Intel ICH5
    Hardware device with all software conversions
plughw:CARD=ICH5,DEV=4
    Intel ICH5, Intel ICH5 - IEC958
    Hardware device with all software conversions
sysdefault:CARD=Audigy2
    SB Audigy 4 [SB0610], ADC Capture/Standard PCM Playback
    Default Audio Device
front:CARD=Audigy2,DEV=0
    SB Audigy 4 [SB0610], ADC Capture/Standard PCM Playback
    Front speakers
rear:CARD=Audigy2,DEV=0
    SB Audigy 4 [SB0610], ADC Capture/Standard PCM Playback
    Rear speakers
center_lfe:CARD=Audigy2,DEV=0
    SB Audigy 4 [SB0610], ADC Capture/Standard PCM Playback
    Center and Subwoofer speakers
side:CARD=Audigy2,DEV=0
    SB Audigy 4 [SB0610], ADC Capture/Standard PCM Playback
    Side speakers
surround21:CARD=Audigy2,DEV=0
    SB Audigy 4 [SB0610], ADC Capture/Standard PCM Playback
    2.1 Surround output to Front and Subwoofer speakers
surround40:CARD=Audigy2,DEV=0
    SB Audigy 4 [SB0610], ADC Capture/Standard PCM Playback
    4.0 Surround output to Front and Rear speakers
surround41:CARD=Audigy2,DEV=0
    SB Audigy 4 [SB0610], ADC Capture/Standard PCM Playback
    4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=Audigy2,DEV=0
    SB Audigy 4 [SB0610], ADC Capture/Standard PCM Playback
    5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=Audigy2,DEV=0
    SB Audigy 4 [SB0610], ADC Capture/Standard PCM Playback
    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=Audigy2,DEV=0
    SB Audigy 4 [SB0610], ADC Capture/Standard PCM Playback
    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=Audigy2,DEV=0
    SB Audigy 4 [SB0610], ADC Capture/Standard PCM Playback
    IEC958 (S/PDIF) Digital Audio Output
dmix:CARD=Audigy2,DEV=0
    SB Audigy 4 [SB0610], ADC Capture/Standard PCM Playback
    Direct sample mixing device
dmix:CARD=Audigy2,DEV=2
    SB Audigy 4 [SB0610], Multichannel Capture/PT Playback
    Direct sample mixing device
dmix:CARD=Audigy2,DEV=3
    SB Audigy 4 [SB0610], Multichannel Playback
    Direct sample mixing device
dsnoop:CARD=Audigy2,DEV=0
    SB Audigy 4 [SB0610], ADC Capture/Standard PCM Playback
    Direct sample snooping device
dsnoop:CARD=Audigy2,DEV=2
    SB Audigy 4 [SB0610], Multichannel Capture/PT Playback
    Direct sample snooping device
dsnoop:CARD=Audigy2,DEV=3
    SB Audigy 4 [SB0610], Multichannel Playback
    Direct sample snooping device
hw:CARD=Audigy2,DEV=0
    SB Audigy 4 [SB0610], ADC Capture/Standard PCM Playback
    Direct hardware device without any conversions
hw:CARD=Audigy2,DEV=2
    SB Audigy 4 [SB0610], Multichannel Capture/PT Playback
    Direct hardware device without any conversions
hw:CARD=Audigy2,DEV=3
    SB Audigy 4 [SB0610], Multichannel Playback
    Direct hardware device without any conversions
plughw:CARD=Audigy2,DEV=0
    SB Audigy 4 [SB0610], ADC Capture/Standard PCM Playback
    Hardware device with all software conversions
plughw:CARD=Audigy2,DEV=2
    SB Audigy 4 [SB0610], Multichannel Capture/PT Playback
    Hardware device with all software conversions
plughw:CARD=Audigy2,DEV=3
    SB Audigy 4 [SB0610], Multichannel Playback
    Hardware device with all software conversions 
     
４．出力の設定、ボリュームの確認、接続の確認
全て確認し、サウンドデバイス(Audigy4) から音声出力できる状態です。

５．ALSAのバージョンの確認
$ cat /proc/asound/version
Advanced Linux Sound Architecture Driver Version k4.4.0-57-generic.

以上