Exactly one year ago today, I posted my very first blog entry on Cocktail Party Physics, never expecting, in a million years, that anyone other than my mom and a few close friends would ever read my ramblings. Little did I know that I was about to embark on a great adventure that would end up, among other things, completely changing my life. The blog has evolved considerably since those rough, early days — and so has Jen-Luc Piquant, who began as a funny little decorative afterthought and has since emerged as a full-blown character with her own distinct personality. (She has opted for purple hair today in honor of this auspicious occasion.) And I can sincerely say that I’m honored to have been so warmly welcomed into the lively virtual salon that is the science blogosphere.
We even received some unexpected birthday presents! The first isn’t really for us, per se, but it makes us happy, nonetheless, to hear that the uncertain future of Brookhaven’s Relativistic Heavy Ion Collider (RHIC) has been resolved, and the facility will be fully funded for 2007. The Brookhaven press release said also that the National Synchrotron Light Source will be "significantly funded" for this year, which is a bit more ambiguous, but still — it’s cause to celebrate, since there was a very real possibility just a few weeks ago that one or both facilities would have to shut down operations entirely until the budget gridlock in Congress could be resolved. (For those who haven’t been following the story, Peter Steinberg has covered it extensively on his Entropy Bound blog.)
The second gift is that we were selected on Saturday as a Typepad featured blog, and were so warmly described therein that we actually blushed. Should any new readers happen along, I finally got around to compiling "The A List" (see sidebar), a dozen or so of my favorite posts over the last year.
The third gift was receiving a very thoughtful, extensive critique on a May 2006 post exploring the acoustics of concert halls — specifically, analyzing what might have been happening, acoustically, at a disastrous Jordi Savall concert. Some people might not consider a critique to be much of a gift, but a critique done exceptionally well, with sufficient tact, is very much a gift — for one thing, it takes a great deal of time (unlike, say, kneejerk criticism). One of the aspects I most appreciate about this blog is the number of knowledgeable readers who stop by occasionally and comment, offering helpful URLs, clarifications, and correcting minor errors. Since I consider the blog my "writer’s laboratory," this kind of input is invaluable. But it’s rare to get the kind of analysis recently offered by Greg Miller, an acoustical consultant with TALASKE, who co-authors an excellent group blog called Champions of Sound in his (no doubt limited) spare time.
Here’s an excerpt from my earlier post:
Alas, the concert was held at St. Paul the Apostle on the Upper West
Wide, a small Romanesque-style house of worship whose architectural
details added up to a veritable acoustical "perfect storm." Unless one
happened to be sitting in the first few rows, the sound was muted,
muddy, and each separate part of the complex compositions seemed to
reach the audience at different times, so that the percussion always
seemed a few beats behind the singers, and/or the instruments.
Needless to say, the evening was an unmitigated disaster. Several
audience members left in disgust, and those who remained to the bitter
end were forced to wander forlornly about the sanctuary in hopes of
finding one of the "live" spots where the acoustics weren’t quite so
ruinous. Since it was impossible to fully appreciate the performance,
our little group instead found ourselves discussing the scientific
aspects of what might be happening to cause the horrific effects.
I made a few minor errors in the post (not an unusual occurrence), most notably equating "resonance" and "reverberation," or at least using the terms interchangeably. That might be okay in a non-scientific setting — musicians conflate the two all the time — but to an acoustician, the terms are quite different, with very specific meanings. While we’re on the subject of reverb, when talking about the optimal reverberation time of Boston’s Fogg Hall, I cited 2.25 seconds. According to Miller, that’s perfect for, say, a symphonic space, but not so great for a lecture hall, which would do better with a reverberation time around 1 second. I also talked about the wood floors in St. Paul’s (where the concert was held) as absorbing sound, when it was, in fact, reflecting it. An honest mistake: the sound from the musicians was muted and muddy, so I assumed there was absorption going on, and erroneously identified the wood floor as the cause. As it happens, wood is mostly reflective, which explains why so many venerated concert halls have wooden floors.
So, if it wasn’t the wood floors, what the heck was going on with the bad acoustics at that concert? It turns out that Miller lived in NYC for a spell and is familiar with St. Paul’s, and thus was able to offer some additional insights, which I excerpt in part below (with his permission). The biggest problems probably had to do with timing and directivity; sound reflections must reach the listener’s ear with proper timing, and at the Savall concert, they clearly didn’t. Per Miller:
"The percussion instruments at the low end of the frequency scale send sound out in all directions fairly evenly. The voices and higher frequency instruments send sound out in one direction more strongly than in all other directions. You were probably hearing strong reflections off the high ceiling from the percussion much later in time than you were hearing the sound from the singers. This could make them seem out-of-time with one another. Musicians also take cues from sound reflected back to them from the room; they may have actually had their timing messed up trying to adjust to one another based on reflections back from the room.
"The sound lacked clarity because there weren’t enough surfaces reflecting sound to your ears within the first 1/12th of a second or so. Your ears heard the sound direct from the voice/instrument… then nothing for awhile… then this blur of reverberation. You need to fill in the gap with what acousticians creatively call ‘early sound’; your brain naturally merges the early reflected sound with the direct sound to develop your understanding of each note/syllable. This is actually one of the reasons that the subway stations are so nice… lots of early reflections, followed by an audible long reverberation, but it’s relatively weak and therefore doesn’t mess up the clarity."
As for directionality, Miller ascribes partial blame to the decorative arches along the sides of the church, which he says "can reflect sound out in some very funny directions, with some odd coloration to the sound. I suspect that they have a lot to do with the dead spots you mentioned."
Clearly, Miller knows his stuff, and we thank him again for shedding additional light on what proved to be a distressing concert-going experience. At least we learned something from it. And since acoustics proved central to this blogoversary posting, I leave you with a link to violinist Jon Rose’s website, courtesy of the always excellent Proceedings of the Athanasius Kircher Society. Rose designs all kinds of unusual instruments, but he also travels around the world playing fences — actual fences — with nothing but his violin bow. His most recent project is "Great Fences of Australia," and you can see a movie of Rose in action here. Clearly, good fences don’t just make good neighbors; they can also make good music.