J.K.Rowling - Official Site

Sounds

There are random household noises in the background. Passing traffic, the doorbell rings, her dog barks, birds chirp, the radio comes on, tunes in, and plays a repetitive tune (for a rather long time), and there is a steady whispering wind. These sounds play constantly even as you move between the different links.

After 8pm, the sounds of passing traffic, chirping birds and the wind are replaced with an occasional owl hoot. The dog still barks, but shorter and softer. No more doorbell either. The radio still plays the same tune.

The moth (butterfly) flutters and the flies buzz. Light switches click.

Peeves' appearance is always announced by a whooshing wind and his mischievous cackle. On the desk top, the pencil cup clanks when he knocks it over and the doxy flutters.

The Portkeys and links "jingle" as you pass the cursor over them. When you click a Portkey, hear a whoosh and a boom as you are transported, and each Portkey makes a distinctive sound when you arrive in the new screen.

• the pink Rubber Eraser ("?"- The Door) plops, 
• the eyeglasses (Links) clink and rattle as they land in the cup,
• the binder clip (Fansites) plops (same as Rubber Eraser), so does the scroll,
• the hairbrush (Extra Stuff) swishes onto its hook (same sound as the papers that swish into place),
• the pencil sharpener (Rubbish Bin) makes no sound, but the sneakoscope and letter swish in, and the flies buzz around.

Old Portkey sounds:

• the hair elastic ("?"- The Door) plopped
• the tea cup (Extra Stuff) and the pen (Links) clink and rattle (same sound for both),
• the key (Fansites) swishes onto its hook (and the scroll plops in),
• the (Rubbish Bin) gum wrapper makes no sound, but the toy top and letter swish in.

Hear a swoosh and the pages rustle as you open the Newspaper, Rumours tabloid, Scrapbook and journal. The pen scratches as it writes Biography in the journal.
The calendar pages rustle when they flip and the page rips off when clicked.

When you click the FAQ question mark link, hear an owl hoot and the flutter of wings as the post is delivered onto the desk. Click the X link and a rush of wind blows them away.

The phone rings a short while after Peeves comes through and at random intervals if the screen is left idle. Click the TALK button while it is ringing and hear Jo's (?) voice say, "Hello, hello? Is anyone there?" (You may need to turn your volume up to hear this, it is very faint.)
The buttons beep as you click them and it makes a tone when the TALK button is clicked.
Dialing a wrong number results in a low toned beep. Dialing a correct number gives a jingling sound.

In the "?" (the Secret Door) link, the wind chimes tinkle. When Peeves graffiti's the mirror it squeaks.

In the "Links" bookcase, the books thump as they land on the shelves.

In the "Fansites" trophy case, a clock tick-tocking replaces the steady breeze.

In the "Rubbish bin", hear the pens crack when they break. Pass the cursor over (no need to click) the toy top, it spins and whistles. The crumpled bits of rubbish in the bin rustle when the cursor touches them, so does the About envelope. Flies buzz.

In the "Extra Stuff" bulletin board the papers swish into place and you can turn the radio off and on.
The radio volume is louder when you enter this screen, as though you entered the room where the radio is located. 
At Christmas time the radio played "God Rest Ye Merry (Hippogriffs?) Gentlemen".
On March 9, 2006 the radio became part of a Scrapbook extra. Click the On/Off switch to hear the "Toots, Shoots 'n' Roots" program by Tilden Toots (as advertised in the Rumours tabloid advert).  

Finding a Scrapbook reward gives a destinctive jingle, similar to the Portkeys.

The Accessibility Enabled version of the site offers a handy Glossary of the sounds.