can't hear sound at all

iam not getting any sound in ubuntu

Did you check sound mixer settings? It is muted by default in ubuntu.

It's definitely headphones jack sense and line sense in Alsa-mixer. I switched them off both of them and now my speakers play the music. Both should be off.

Could you please be more specific which one i should be mutted, i already tried, but it wouldn't solve the problem, i still can't hear any sound from my notebook's speakers (lenovo y400).. just only from headphone.

since ypdating to ubuntu 8.04 i have no sound. Laptop is dell inspiron 1525. New to ubuntu please can anyone help?

Audio trouble with Ubuntu 8.04 some common checks

-- If you are using a laptop, your laptop may have a keyboard function to manipulate your sound.
   Check that. Your laptop may have a keyboard control to mute, increase and decrease sound.
-- Please check your sound devices volumes are to a high level double click on the top right loudspeaker icon you will see a mixer
-- Please make common test from menu System->Preferences->Sounds
   if you are using PulseAudio please read: http://www.pulseaudio.org/wiki/PerfectSetup or try if using ALSA things go better
-- If you have two audio cards - please disable the on board audio card using BIOS setting, please check with this terminal command:

   lspci | grep -i audio

-- Please be sure your pc are starting with the generic kernel press ESC at boot when you see the GRUB row then select the "kernel.... - generic" row
-- Please be sure all needed kernel modules are installed to make this check and install them:
  So open a Terminal from the menu Applications->Accessories->Terminal and type:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install linux-ubuntu-modules-$(uname -r)

give your user password when requested, you don't see nothing when you type it, then press enter.

Then reboot your pc.

-- Be sure your user is member of audio group
Then open a Terminal from the menu Applications->Accessories->Terminal and type:

sudo adduser $(who am i | cut -d" " -f 1) audio
sudo chmod 660 /dev/snd/*

give your user password when requested, you don't see nothing when you type it, then press enter.

-- Please try to watch what audio cards are detected on your system please type:
asoundconf list

if more than one sound cards is detected by your system to set the default soundcard

asoundconf set-default-card PARAMETER

change PARAMETER with the name of a one detected sound card

-- Please try to delete making a backup copy of this conf files
mv .asoundrc .asoundrc_old
mv .asoundrc.asoundconf .asoundrc.asoundconf.old
sudo mv /etc/asound.conf /etc/asound.conf.old

Please take a look at this http://ubuntuforums.org/showthread.php?t=205449

-- Please try to discover if there are any process they are keeping the /dev/dsp locked
ps -edalf | grep -i dsp

kill them using this command:

kill -9 number_of_pid

Reboot your pc to see to check if you sound now work.

---------

If you microphone seems don't record your voice please open a terminal and type

alsamixer

and press tab to switch in view to [Capture] section, and then pressing space on mic and mic boost aid

If you are using Pulseaudio and you have some sound issue with sound apps for example with flash contents please read http://www.pulseaudio.org/wiki/PerfectSetup and this http://ubuntuforums.org/showthread.php?p=4928900

Hope this helps