Interesting feature! Wish I had that option on my devices, combined also with something similar for sounds.

Yes! It annoys me when a scene with characters shouting is much louder than a scene where characters are talking with hushed voices, as an example.

We know a shout was louder at the source, but the decibel level at our ears is proportional to 1/distance squared, meaning hushed voices aren't necessarily any quieter "in real life". I'd prefer suspenseful and dramatic scenes both play at similar, comfortable levels. I don't want to have to adjust the volume up and down so I can understand one scene and then not have it be disturbingly loud in the next. In practice, I just use subtitles to circumvent the "difficult to understand" problem.

What you're describing is called dynamic range compression, and mpv can be configured to do this in multiple ways.

Back in the physical media days, it was pretty common for DVD/Bluray players to include this feature. Unfortunately it's not something that streaming app developers thought twice about. Your TV or streaming box also may or may not have the feature.

It's a problem for me between being half deaf anyway and Google not adjusting source streams to any sort of minimum decibel level. So listening to the local Pacifica station with no adjustment is about half the loudness of the local NPR station. Pleas to correct the audio level have fallen (heh) on deaf ears, so my donations and my listening has moved elsewhere. Sorry, local radio. I'd support you if you'd support me.

Unfortunatly cinemas either don't use MPV or don't use this feature, so while dialog is audible, gunfire is often way too loud for me

Huh, I actually want this when I'm at the cinema, for immersion. Just not when I'm watching a movie at home at 11pm.

It's interesting that even podcasts, which you'd think would be more focused on audio considerations, don't do this, either. I'm mostly thinking of Dan Carlin's podcasts, where sometimes he goes a weee bit quiet. (And Shadows of Utopia, which I have to jack up the volume for the entirety of)

(insert caveats about: artistic effect; I have zero audio engineering experience; podcasters definitely do some things in this vein e.g. https://www.reddit.com/r/podcasting/comments/10oqvpm/podcast...)

Doesn't that depends in the sound system setup ie hardware? I tried vehemently to fix it once with JamesDSP with no avail. My understanding then was the need for hardware support like Dolby or something. It was always an issue with music and dialog.

I'm watching a tv show, and while I'm sure a crying baby is appealing to a parent to the point they'll run at it, I'm now sufficiently annoyed that I'm just skipping past the crying baby storyline.

Part of this is psychoacoustics... Our hearing sensitivity is peaked near a crying baby frequency regardless of dBa.

Poor audio systems are also to blame for this

You want a 3.1 system (at least) and increase the center channel

No: The problem is directors who love mumbling, audio people who have no idea how to record and balance audio properly, and media players that can't or aren't configured to properly downmix audio tracks as appropriate.

It is absolutely possible and honestly standard fare to have properly balanced audio playing on the $1 tin cans found in TVs and laptops.

I have a 3.1 system and it's still terrible on many movies made after 2010ish.

P.S.

Even properly mastered content will not work well in a noisy environment (e.g. a car or if you have a dozen fans going because it's summer). Here's my ffmpeg filter for such situations (including a stereo downmix, for those without a center channel):

   aformat=channel_layouts=stereo, compand=0 0:1 1:-90/-900 -70/-70 -30/-9 0/-3:6:0:0:0

No, you'd be surprised at all the random crap they put on the center channel nowadays. You just need an equalizer and use it to boost the frequencies of human speech. A lot of AVRs call this "dialogue enchancer", but you can do it easily in software

There is a preset for EasyEffects which can handle that: https://github.com/Digitalone1/EasyEffects-Presets

I haven't tried it for music, but for videos it works pretty well.