NASA's helioseismology recording made it to the "sounds of summer" 6pm
slot (Big Ben chimes are broken again) on BBCs Radio 4 evening news
programme PM. Click on the link to get to minute 53 for start of the
piece.

Available on play it again for the next 7 days at

http://www.bbc.co.uk/radio/aod/mainf...?radio4/pm_thu

Click on the >>15m button 3x and >>1m 7x to get to the start. I expect
it is on the NASA website too.

If I didn't know better I would say it sounded like AC mains hum!

Regards,
Martin Brown