It sounds like water damaged already the sounds facility and you were definitely too quick with starting your laptop again. It should stay longer without any electricity, battery and during that time you should search for help.
I am afraid your laptop was already damaged and not by the water and electricity but your too fast actions checking if everything working OK. If you want to try you can take your laptop to Fastechnet shop but please do not promise yourself too much - standard checking of the laptop costs £20. Replacing the whole motherboard costs around £150. If this is damaged permanently, you can buy an USB sound adapter which gives you headphones facility. It costs up to £10.
OK, the summary of Marek's fabulous response is: if water infects your laptop/ipod/iphone/electronic device then switch it off ASAP and don't switch it on again until you're positive it's completely dry. Water shorts circuits.
Oh but if you spill tea/coffee/chai on it and you take sugar then you're stuffed.
Thanks for these replies.