No sound through speakers in Lucid Lynx

Strange issue to spend a couple of hours over the weekend! Was trying to watch some catchup-tv on my laptop, the video was perfect but there was no sound from the speakers. Without much thought, I just stuck my headphones into the jack and wallah, there was sound! So something was wrong here. This laptop had the most recent updates on Ubuntu Lucid Lynx as of July'2010. After a few pages advising me of technical support for hardware issues and soldering problems, I was just trying to see which were the "sound-manager-applications". Turns out - ALSA and PulseAudio. Reinstalled ALSA and rebooted - no results. Didn't guess initially that I should try the same with PulseAudio. But that was the solution!

sudo apt-get remove pulseaudio

Reboot

sudo apt-get install pulseaudio

Sound should be up straight-forward. Reboot, if necessary.

If the sound is low/feeble -
(a) System-->Preferences-->Sound Check sound levels.
(b) Do the same with alsa-mixer

What is A2DP?

A2DP: I saw these jargons all the while, although I seem to have used it, never bothered to know what it was! Me being me, this was unacceptable!

So, here it is - A2DP stands for "Advanced Audio Distribution Profile". The Bluetooth Core has a protocol stack, over which, devices can add different profiles for each service that they provide. A2DP was introduced for "streaming", superior quality stereo music over traditional bluetooth technology.

There are other profiles as well, the ones that most of us have experienced - HeadSet Profile (HSP), HandsFree Profile (HFP), Human Interface Device Profile (HID) etc.

Interested in knowing more? I suggest reading this on Wikipedia.