I have the same problem, when i use tv capture card no sound on client... but now the broblem is solved.
Please check your device with commandline type dmesg, this command will show you where is the device video and audio (dsp). In my case I use debian sarge with 1 tv tuner and dmesg result that my tv card is detect in /dev/video0, audio is /dev/dsp1 for digital and /dev/dsp2 for analog.
Ok.. from this I try to open vlc with commandline.
vlc --color v4l:/dev/video0:adev=/dev/dsp2:norm=0:size=320x240:frequency=583250 :sout="#transcode{vcodec=mp4v,vb=256,scale=1,acodec=vorb ,ab=32,channels=1}:standard{access=http,mux=ogg,url=192.168.1.222:1235}"
And this is work.
Note: I have try many audio codec, but only vorbis can used maybe vorbis audio codec is free for linux not like the other.
regards.