Long day.
My house has been chirping. Despite the amazing human
mechanisms for locating the direction of a sound source,
there are certain sounds it is very difficult to get a
direcitonal fix on. (As an extreme case of this, I recall
being in a fast-food restaurant with
madbodger,
standing at the counter when the French-fry machine started
beeping. At the first beep, a worker started to turn toward
the machine. The second beep was nearly matched for pitch
and timing by
madbodger, and the worker looked
slightly confused. The third and successive beeps were
matched for pitch, timing, attack, and probably phase, and
the fast food worker's eyes went wide as he looked around
the place trying to get the direction of this now Coming
From Every Direction sound. He eventually decided that even
though it didn't sound like it was coming from the direction
of the fry machine, it was the fry machine noise so it had
to be that. But I digress. That wasn't what I sat down to
write about at all. I just wasn't sure when else I'd have
such an excuse to tell that story.)
My house has been chirping. It's a chirp that's hard to catch the direction of, and at such long intervals that an impression of the direction of the sound never has a chance to build up.
My house has five smoke detectors. Well, five that I've found anyhow. I just went through all five of them trying to figure out which one was chirping -- I only had one set of batteries handy. My house also has high ceilings, but fortunately most of the smoke detectors can be reached from a stair (if you're nearly as tall as I am, anyhow). I'd been to all three floors before I remembered there was a smoke detector in the basement.
I started loading the car sometime fifteenish in the afternoon, and got to the site for the gig a little after sixteen o'clock. A couple of hours later we had the knobs all twiddled correctly on the sound system, and it was time to start performing. Oops, no nap. We played at various times during the event, and (with the dancers) bookended the feast. We couldn't do all the teardown and packup immediately afterwards because of the ceremony that followed the feast. I pulled out of the parking lot to go home about half past midnight, and by the time I finished unloading the car and trying to figure out where to set things down such that I'd still be able to walk from one end of my house to the other, it was a third past one.
Long day. Very tired musician. I've got some thoughts about how the evening went to express, which I may or may not get around to writing later.
When I looked up before getting out of my car after returning home, I saw a kitty in the window. Perrine was perched in the living-room widow, looking at my car. I'm going back to bed now, where my cat can curl up secure that I'm within sight. Me, I'm barely keepin' my eyes open.
Kitty in the window and a rat on the sidewalk. I think the rat was out of Perine's field of view most of the time I watched it. Got undressed, fed the cat, hunted the chirping smoke detector, sat down to write this, dozed off in my chair, woke up again, decided to call this finished whether it is or not... Much of me hurts. This was a long day.
(no subject)
It was a nice digression, though. And it is good to be warned of odd people... ;)
The birds have a number of different signal calls. The warning signal usually is a short, high-pitch chirp. One can easily imagine that the natural selection has guided the warning call to be difficult to get a bearing on. The predator will hear it, but is not able to home in on the call.
Counterproductive as it may seem, I understand the designers that put a "Low Battery" warning light on their product. I've been driven crazy by the once-an-hour chirps, too.
(no subject)
Mel frequently sits in the dining room window to watch me do the "Let the dog out, bring the paper, and then the cat's dishes, in." ritual.
I don't think James leaves that bench by the window when I leave, and unless he's been barking and crated, is always there when I come home. Perrine strikes me as that sort of beastie.
Ooh. Time to bring the doggie in and put some cat food out. Morning Hokie-Pokie. Minus "shake it all about" part. Too early for that.
(no subject)
Good gig. I hope you can get some rest today.
sound location
the main cue is phase differences.
At high frequencies, your head is a few wavelengths wide, and this doesn't work,
so the systems shifts to a time-of-arrival mode.
This is much trickier, as you have to a) get another sample after mode switching,
b) you only get one edge per sound, and c) if the sound doesn't have a sharp
attack, it's hard to pin down the edge. The last effect is magnified by the fact
that it takes a little while for human ears to detect a quiet, high frequency signal,
effectively destroying the sharp attack.
There is a third method, based on differential frequency amplitude and phase,
which depends on the convolutions in the external ear to form a filter that encodes
angular information (this is the sole method for hearing elevation as opposed to
azimuth differences).
Cats have us utterly whipped on all of the above, even before their incredibly useful
independently rotatable pinnae (which also need a second sample to get aligned and
useful). I've often used my cat to pinpoint sounds for me -- even a tiny little wheep
will normally be noticed and localized. You can read off three indicators (each ear
and the direction of gaze) -- however it's up to you to determine which reading is
applicable for the sound you currently find interesting (the cat will have her own
opinion of what is and is not interesting). And it's possible the cat will have already
investigated and dismissed the sound you're after. It is possible to communicate
to a cat that there is a sound you'd like to know more about, and some cats are
willing to help out here (they're quite aware that we're bumbling fools when it comes
to hunting). However I can't do this reliably, or explain how it's done, just relate that
I have managed to encourage cats to tell me where the blasted noise is coming from.
This trick is much easier with dogs, but I don't usually live with dogs.
(no subject)
Madbodger in action