Mark Atwood (fallenpegasus) wrote,
Mark Atwood

Another scan, another day

The power! The phenomenal cosmic power!
The electrical power failed in my home last night. It wasn't a big deal, it happened within a few minutes of my shutting down the laptop to go to sleep. Just as I was drifting off, I heard the bathroom vent fan clatter to a stop (I leave it running constantly to act as an air circulation sink, because otherwise my home gets rather stagnant), and then the UPS started to beep. I just let it go, and went to sleep. Whenever I would wake up in the middle of the night, it was weird to hear no noise. Usually there is the bathroom fan, an air filter, and the computer's case fans running 24/7. At about 6am I woke up to a flashing yellow glow. It was a couple of PSE trucks parked in front of the building, working over a manhole. The power outage seemed localized, just my building and the next one. The power came back online again about the time I was drying off after my shower.

There's still a brain in my head. I'm not dead yet.
I went back to Ballard Swedish Medical for another followup MRI. Driving back over the 520 bridge at 10am reminded me why I moved to Kirkland, just to get rid of the commute. The process of the MRI was just like the previous two. Except that the fact that I forgot to eat dinner last night, and mostly skipped breakfast this morning meant I was dehydrated, which made it somewhat of a challenge for the tech to find a vein for injecting the contrast. The resulting images looked pretty much just like the last times. We'll see what Dr Travis and Dr Steege think. Tomorrow I come back, pick up all my films, and then visit Dr Yue, an Ear Nose & Throat specialist.

My Ex
While I was on the west side of Lake Washington, I drove up to Crown Hill to pick up my ex for lunch. (She just set up a LJ herself at jezel. Bwa-ha-ha. Another one joins the Collective..) We drove up to the University District. In her car, since I was a dipstick, and left my lights on. Again. I think my battery is dying, I had only left them on for 20m or so.

I was hoping to find a copy of Butenhof's Programming with POSIX® Threads at the UW bookstore. No joy. So we ate lunch at a Greek place, bought a couple of candles at Gargoyles, and picked up the first volume of the collected The Authority at Zanadu, because I had heard interesting things about it. Then we drove back to her place, jump started my Jeep, and I headed back towards Eastside.

After returning to work, I started calling down local eastside bookstores. "Let your fingers do the walking." Finally I found it at the Bellevue B&N. I could have gotten it for pretty cheap off used off of Amazon, but I don't have the couple of days to wait.

Over the last couple of days, I've been learning cool things about audio and telephony. The same technology that resulted in the invention of the MP3 is also revolutionizing both telephones and also testing telephone quality. There's a whole alphabet soup of telephone audio codecs, with names like G.723, G.726, and G.729, which do psychoacoustic tricks to take a 56 kilobit audio stream, and jam it down to between half to less than a tenth that size.

Similarly, the technology of psychoacoustics is being used to revolutionize measuring audio quality. Fifty years worth of engineering knowledge about signal analysis is being supplemented by the observation that as neat and as techy as an oscilloscope and a spectrum analyzer is, the human ear is no more a spectrum analyzer as an eye is a camera.

The magic TLA is "MOS", for "mean observer score". Originally, MOS was calculated by taking dozens of trained listeners in sound booths, and have them listen to and compare streams of recorded audio, and rate them. This was very slow and expensive. But the same tech that makes MP3 possible also makes automating this process possible. The magic words here are things like ITU P.861-1986, PSQM, PESQ, and so forth. Basically, there are machines that can listen to two streams, model the human ear and brain, and tell you how good the audio quality is.

It's been way fun to play with.

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