Apologies for the breach of netiquette in replying to myself, but I have news of progress. Not much, but some.
Using Knoppix 4 I can get sound recording applications to record sound from the built-in mic on my Thinkpad. So, the hardware is fine. I have recording working on another sarge box here, so I can see that the recording apps do work under sarge (not too big a surprise). ... but I'm still stumped trying to get (e.g.) Audacity (thanks James) recording from the mic on my Thinkpad. I do hear sounds from the mic on the speaker (as I do when under Knoppix, and on the other box). I can control the volume of the mic on the Thinkpad and can mute it through the Gnome volume control. But recording apps get nothing. I'd be happy to R an FM or a troubleshooting guide if someone could point me to one. I have Googled, but have not found anything that has helped so far. Many thanks. Bruce -- Make the most of your skills - with OpenSkills http://www.openskills.org/ -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html