I am thinking of how to apply the "Well-insulated" virtue (Covenants p114) to a lab through magic, rather than by having to thicken the walls and drape heavy curtains everywhere, taking up precious space (1 point of occupied size in Covenants terms) and so on.
I start with the base guideline PeIm 3 "Destroy an object's ability to affect smell or hearing" to destroy incoming sound. An imaginem base individual is an equivalent amount of noise to that made by one human. Now, the tricky part is which target is most applicable - do I choose Group (to affect a whole bunch of noises coming in, up to the equivalent of ten people) or do I choose Room to reflect the fact that I'm affecting walls and floors? I think I will need to add Part as well as I don't want to destroy sounds made within the room so I can still cast spells normally.
So far, I get PeIm 3 +1 touch range +2 sun duration +2 group/room target +1 part for total 25 for a spell, or if I want an enchanted item make a level 29 (25, +1 with 2 charges/day and +3 sunrise/sunset trigger) item. Does that sound right?
I am assuming you are using the new design for container, using a "Dynamic" setting, allowing item (in this case sound) to be affected as they enter the area ?
It is a bit of a strange interpretation of "Destroy an object's ability to affect smell or hearing", as I would interpret it more in the sense that no sounds escape the room targeted by the effect.
You probably would need to run that by your troupe to agree on your interpretation.
Alternatively, I would suggest ReIm, since the effect your are describing is more akin to a ward against sounds. Unfortunately, there is not specific guideline for this effect. Base 4: Make an object appear (to one sense) to be contained in or attached to another object defined at the time of casting (for example, make someone’s voice appear to come from within a bag. In this case with an interpretation that your are preventing "one sense" to enter the area (instead of containing it to an area).
Again, subject to your troupe approval. There seems to be no straight answer using existing guidelines.
Sadly, the ReIm guidelines in the corebook don't mention warding. Using an analogy with ReIg, would sound insulation be "slightly unnatural" (if you're completely muffling sound rather than the natural effect of a wall) and be a base ReIm 4, or is this natural enough a base of 3 would work?
I could also consider MuIm and change sound to a different sensation, but would a wall that glows when people outside make a noise be distracting?
I used ReIm 5 as the guideline for "ward against species of one sense [Touch, Ring, Circle]" for a hedge tradition in my game. Hasn't come up yet but seemed reasonable.
And don't MuIm the auditory species into visual species; change them into gustatory species (taste). Who cares if your wall tastes like roast chicken when people outside make a noise? Presumably, you don't often taste your sanctum's walls. (exception for Bjornaer with dog heartbeasts, I suppose.)
Take a look at Circle of Undisturted Rest in Magi of Hermes (p.133). The spell uses ReIm Base 3 to do pretty much the same thing, although using T:Circle and D:Ring.
Yeah, ReIm or PeIm to ward/destroy sound species is good options.
Theoretically, you could also do a MuTe/MuHe on the walls to make them absorb sound better. A ReIm to make the sound come from a small box in the corner, allowing you to keep track of notable things like explosions while leaving sound muffled.
(I am so used to 'insulation' referring to heat control that I was very confused for a moment.)
A ReIm ward against sound might make the room seem very loud, as sound is not necessarily stopped; it may be reflected. (If so, a visual ward would seem to make a mirror. If not, it would make a blank, black, white, or gray zone.) Perhaps this might be a Sigil expression issue.
Your point about sound reflection is very true, tho I don't know how Mythic Europe thinks about echoes. Does sound reflect or power through a solid surface?
It does make me think the MuTe Sound Absorption is the easier way to go.
Rego Imaginem may be missing Warding guidelines, but it does have guidelines for "make object appear (to one sense) at X distance"...
Are you a Tytalus wanting to insulate your laboratory? Enchant it so that all those distracting noises are teleported to the laboratory of whomever annoyed you most recently! You'll probably need a Container Target and need to be clever about what Arcane Connection you use, but imagine the bragging by hinting you'll be doing at the next Eristic moot...
There are some very good ideas here. One of the things I love about Ars is all the different approaches you can take to a problem, and people have made many suggestions about ReIm and MuIm as opposed to the PeIm that to me was the obvious approach.
Another option jumps out to me is a Muto Terram (or Muto Herbam) - Change dirt so it is slightly unnatural (deadens sound, or possibly eats it). Might have a requisite, but might also be something you can apply without having to do complicated things with rooms and rings and all that.
Base 3 (Change to be slightly unnatural) +2 (affect stone*) + 1 Sun +1 Touch is only MuTe(Im) 15, saves you a few levels. You'd have to cast it every day, and probably on every wall/floor ceiling, but assuming you learned it as a Formulaic that takes less than a minute, and having a meditative practice of walking around the room at the start of your day preparing the space is like, basic magic practice IRL.
If you've got stone walls with dirt-infill, you can lose the +2. There isn't a canon equivalent for Herbam but I feel like it would be about the same by analogy, and you again lose the +2 from stone, dropping it down to just +5 (then maybe you make it +2 group, so it's a total of 15 Enchanted Object; lots of room to slap on the standard +4 Goes On Forever upgrades, if you had the Lab Totals for 'em).
Note that per the Covenants (p.122) rules for spells in the laboratory, you'll want to make it an enchanted item, not a spell.
Using a non-Ritual spell to enhance a lab either reduces the Safety characteristic (and improving Safety is the primary benefit of Well Insulated, so it'd be self-defeating) or increases the Warping characteristic (not the phenomenon from the Long-Term Events chapter in the core rules, but the tendency for a laboratory to produce odd results, as described on Covenants 111 / the DE draft Chapter 8 p.292).