Nothing beats baudline, this has been my go-to signal analyzer tool for decades. It makes me sad that the project has not seen any updates for a long time, and it is getting harder to get it to run proper on a modern OS.

I believe the author considered releasing the source code under some permissive license long ago, but decided not to because the project was refused by freshmeat.

Sigblip: if you read this, please re-consider so baudline can get a second life!

http://baudline.com/

The demo video [0] is a bliss of nostalgic editing!

[0] https://youtu.be/jDCRvBTwXuE

See also, Praat:

https://www.fon.hum.uva.nl/praat/

It's bit more geared towards speech analysis for phonetics in linguistic research and education. Solid tool even though the UI is hot garbage. No screenshots, alas.

This line in the readme cracked me up:

> You have to be Java

Sonogram visible Speech