This is driving me nuts. I know that my speakers are working because I've tested them. I have three different mics on the system: the built-in one in the Lenovo laptop, one in my Logitech webcam, and an Audio-technica 2020. I have tested each of these in Sound Recorder and they work.

But when I do a capture via the Record Monitor in Kdenlive, the video is recorded just fine, but I get no audio.
During the recording I do hear my voice echoed through the speakers (if they're left on) together with something that sounds like sonar pinging :-). But when I play the mp4 file in VLC Media Player ... no sound.

In terms of configuration, I have the Audio driver set to "Automatic". I've tried playing with the other selections and gotten no further. I can't see how to select a particular mic, but nothing seems to work at the moment.

Any help will be appreciated.

The audio driver is for playback. Kdenlive uses ffmpeg to capture from Video4Linux and audio.
Settings > Configure Kdenlive > Capture > Video4Linux > Capture params

Maybe OSS capture does not work on your system. FFmpeg added ALSA support sometime in 2009, but Kdenlive defaults have not been updated (users' FFMpeg versions tend to lag a little). Try changing "oss" to "alsa" and "/dev/dsp" to "default", "hw:0,0" or "hw:0,1"