[squarefoot]

Many people use quality audio cards plus software to do this.

http://kokkinizita.linuxaudio.org/linuxaudio/

Look for Jaaa, near the end of the page.

Also interesting, although semi-unknown:

https://www.sillanumsoft.org/

[buescher]

Dynamic analyzers are really cool. I'd like one. Too bad they go for silly prices.

Yeah, the niche seems to be filled by software and either sound cards or equivalent USB acquisition hardware.