I tweaked the default static drill sounds to be quieter and mono. (You can choose how much quieter you want them to be by picking the -8, -4, or -2 db reduction; -8 is *much* quieter than -2.)

https://drive.google.com/drive/folders/1AjVkk-OQXZkOFebGfBWXYeJQre4IQnPF?usp=sharing

To install them,

1. Open up your Steam Library page.
2. Right-click on 'Space Engineers' and choose 'Manage | Browse local files'.
3. In the address bar of the Explorer window that will open, click on 'steamapps'.
4. Click through 'workshop', 'content', your steam ID number, '2493091475', and 'Audio'. This will place you where the static drill sound files are.
5. Open up the chosen 'ResourceNodes_Drill_Sounds' .zip file.
6. Select and drag the two .wav files from the .zip window to the Explorer window. (You'll need to confirm that you want to replace the files.)

You are now done. To change the volume level again, just follow these directions with a different .zip file. To restore the original volume, just delete the .wav files; the originals will be redownloaded.

Cheers!