[RPG] How should Thaumaturgy’s “three times as loud as normal” be interpreted


This may be a bit of a silly question, but it came up during playing and left me wondering. The spell description states that your voice booms "three times as loud as normal", but it leaves open how the volume of a voice is measured.

Two common ways to measure the volume of sound is to measure the pressure difference the sound causes as it travels through air and optionally to transform this level on a logarithmic scale (the Decibel scale). This table lists several things to reference. For example the upper end of a normal conversation sits at 0.02Pa or 60Db.

Now if we mean "three times as loud" on the linear pressure scale, that elevates a normal talking voice to the volume of a TV set. Not very impressive. If we mean "three times as loud" on the logarithmic scale, that comes out above the volume of a stun grenade. Very impressive, though probably a bit unbalanced for a cantrip.

Obviously neither of these interpretations is what the spell creator had in mind. But, then what is?

Best Answer

Ask your DM

This is one of those "get creative" spells like Prestidigitation that is (I think) deliberately left fairly vague because it is meant to be an adaptable utility cantrip geared towards the narrative/problem solving aspect of the game.

A voice can be a whisper, a conversational tone, or a full throated yell. Nevermind how to the amplification is calculated, even the starting sound is subject to a lot of variability. The point is that the voice is amplified.

A player attempting to use Thaumaturgy should inform the DM what sort of effect/benefit they are aiming to achieve and work with the DM to figure out if/how that is achievable.

As Black Spike points out in their good answer, one very easy solution to implement would be to simplify the question to how far the voice carries (since this is probably the more relevant question). If it's three times louder, it can be heard at three times the distance it normally could be heard.

While the Sourcebooks don't seem to quantify this distance in any way, the (an) official DM screen does include this info about audibility:

Audible Distance

Trying to be quiet 2d6 x 5 feet

Normal noise level 2d6 x 10 feet

Very loud 2d6 x 50 feet