> The biggest problem at many parties is an endless escalation of volume. If you know how to fix this, let me know.

If there’s a band: if you’re the host or the person paying, just ask them politely to turn the volume down every ten minutes or however long it takes for the volume to drift up. And it will drift back up, because very few bands are able to keep their hands off the mixer.

For conversational volume, either go outside or use serious acoustic treatment. The latter may be challenging.