Right, Jack, thanks - I've seen RT60 charts mentioned in room treatment analysis - is this is a measure of sound reflectivity in the room?. So is there a range or guideline for what is a good range/bad range or is the answer - it depends
Sorry if this is room treatment 101.
The answer is it depends
A 0 value is anechoic, we know that that is totally unnatural sounding and thus uncomfortable. Inverse Square Law anybody?
What I was actually suggesting is that various places categorized tend to share ranges of averaged RT60 values (RT60 from 20Hz to 20kHz). A studio control room in a range centered around .02sec all the way to cathedrals perhaps as high as 8 or even 9 seconds depending on the longest direct reflection route. What I was driving at is that when we imagine how a sound event "should" sound based on our personal experiences, this is always tied to where we imagine the sound event would occur and where in that place we be situated. It depends
What we have to remember is that reverberation is a blending of reflected sound images. At times it can sound beneficial like when we sing in the shower
So use of reverberation can be double purpose. It can be used to enhance(or degrade) tone, because it adds body, as well as be used to provide spatial cues. In my limited experience I've found that these two are difficult to separate thus leading to "it depends". That being the particular situation. A restaurant may have any RT60 dictated by its size, the ideal for a fine dining restaurant would be a low value for intimate conversation. You wouldn't want this in a fast food joint as too much comfort will slow down turnaround time. It's actually a very fascinating part of architectural design that has really been gaining awareness and traction in the last few decades.