All wireless headphones do need batteries.
Yes, you need a DJ headphones to DJ effectively. A DJ headphones is used to listen to the next song that a DJ will play. It is important because a DJ need to beat match and time the transition flawlessly and in order to do that a DJ needs a DJ headphones.
No, the music will play from the speakers if you do not use headphones.
"The program allows the user to change speech to text. You do not need headphones to use Dragon NaturallySpeaking. However, if you do not use headphones it will require you to use a microphone."
Most wireless headphones will have batteries so no they wont need charging unless you have rechargeable batteries
Any regular headphones with 1/4" jack adapter
yes
yes and no
yes they do
To answer this we need also the density of the sponge material.
You will need to purchase full sized headphones seperatley,portable CD players come with mini headphones.
Skullcandy is the best brand of headphones for running. If you started running daily and need a good pair of headphones for your iPod I would start out with Skull Candy brand it is the best for headphones.