After one week hacking I finally found out how to play sound or do text-to-speech on Odroid U3.

What you need to do is simply:

    su root
    adduser odroid audio

then when you typegroups odroid , you will see that the user odroid is in the audio group. Then you can play sound through the 3.5mm jack

Now you can have fun playing music and do text-to-speech using espeak or festival.

Additionally, if you want to use ROS sound_play package to do text-to-speech, according to this, you need to install jackd:

sudo apt-get install jackd qjackcontrol
sudo gedit /etc/security/limits.conf

add following in its end:

@audio   -  rtprio     99
@audio   -  memlock    unlimited
@audio   -  nice      -19

and start jackd by

jackd -d alsa -d hw:0

You can put this in your startup programs.