Q: Is this a mod of excellent quality?
A: It seems fine! It may not work for any and all entities from all mods, but it should work for most, and I can add compatibility if the need arises.

Q: How do I find entity IDs?
A: You can find both type and name ID on the wiki. As for entities added by mods, you can at least find the name ID by pressing F4 in-game, selecting the option "show-debug-info-in-tooltips", and then hovering the mouse over it to see its info.

Q: Please explain how to use the startup settings!
A: Fine. To modify all entities belonging to a prototype, you may add the type ID to a comma-separated list in the first field in startup settings. You may write a colon (":") in front of the ID and, as a prefix, add up to three letters ("aio" corresponding to "active", "idle" and "other" sounds) to select the groups of sounds to modify, and a number (0-100 corresponding to a percentage value) to modify the sound volume. As an example, "aio100:radar" does nothing, but at the default sound volume factor of 0, "aio:radar" and "radar" completely mutes the entity. In fact, so do "ai:radar" and "a:radar", because this prototype, like most, doesn't use any idle or special sound categories. For the same reason, "io:radar", "i:radar" and "o:radar" do nothing. (Actually, only the accumulator uses the idle sound property in unmodded Factorio, and only a few entity prototypes use various other sound properties, such as construction & logistic robots, roboports, agricultural towers and asteroid collectors.) Example: "75:transport-belt,i50:accumulator,ao25:roboport,radar" reduces noise of all transport belts by 25%, the idle noise of the accumulator by 50%, both the working sound and special sounds (top entrance opening/closing) for roboports by 75%, and entirely silences the radar.

Q: What to do if the settings reset by accident or because of a mod change?
A: Well, I do recommend keeping a small backup text file, in case the lists get long. Anyway, here are the settings that I personally use, for easy copy-paste:

• transport-belt,underground-belt,50:splitter,75:pipe,75:pipe-to-ground,75:storage-tank,electric-pole,accumulator,radar,beacon,roboport,spider-vehicle,heat-pipe,construction-robot,logistic-robot
• 50:heating-tower,a:agricultural-tower,50:pump,valves-one_way,valves-top_up,valves-overflow,i:flare-stack,i:flare-vent,i:electric-incinerator,creative-mod_energy-source,creative-mod_passive-energy-source,creative-mod_energy-void,creative-mod_passive-energy-void

Q: Do you have any plans to expand on the mod?
A: Maybe! The mod is already plenty useful, but in principle I would like to ensure that it works for all of the special sound categories, and not just most of them. I may also want to expand the mod to work on other things than just entities.