May 30, 2005
Music Thing has published histories of the
Macintosh startup sound.
Newsweek magazine is running a cover story this week on
noise-induced hearing loss:
Of course, noise isn’t the only culprit. “Even if you spent your life in
the library, you wouldn’t hear as well when you’re 70 as you do when you’re 20,”
says Dr. Robert Dobie, professor of otolaryngology (ear, nose and throat)
at the University of California, Davis. But who spent their lives in the
library? Not Kathy Peck and her fans; not the folks riding jackhammers on
road crews, and not the firefighters and cops dashing to the rescue with
their sirens screaming. Even pediatricians have been known to develop
hearing problems after years spent around crying babies.”
Product & Research News:
- A Boston University graduate student has
developed an underwater acoustic sensor array
based on off-the-shelf components to aid in national
- Applied Minds, a California firm founded by a computer architect and an
industrial designer, is marketing an
to help guard privacy in open office spaces.
- Students at Western New England College got a close look
at technologies used to
suppress aircraft engine noise.
- The Tampere University of Technology has developed
“The Noise Shirt”
to help alert workers to excessive noise exposure.
Recent articles of note from Home Theater Blog:
- My about face on extended warranties:
“We now all but insist new flat screen purchases included an extended
warranty and if the customer declines, we bluntly inform them of the
consequences. This may seem a little harsh, but we’re not talking about
$300.00 DVD players that can be considered almost disposable, in the
scope of a larger project. We’re talking about a display that on average
sells for four thousand dollars or more.”
- Smaller, intimate home theaters:
“Don’t get me wrong, I’m not complaining, it’s just that often
these 40x60 monsters are owned and used by families with 4 or less
members. Not surprisingly the construction based on square footage alone,
often exceeds all other costs combined.”
[Tag: Home Theater]
May 10, 2005
Short takes, some old, some new:
Are your noisy neighbors bugging you?
Get some payback!.
Non-acoustic sensors detect speech without sound
I had asked
about a report indicating that
idiots enthusiasts are mounting
train horns on cars.
Looks like it’s true.
There are lessons to be learned, both technical and political,
in this story about an
ill-fated noise barrier.
Sound control as art:
Sound-Dampening Cardboard Wall Sculpture.
It would be nice to see some 3rd-party test results.
Perhaps there is a rational explanation for
at live events? (Other than ‘the performer can’t sing,’ obviously.)
From ABC News:
Hearing Loss: A Preventable Problem.
Interesting confluence of thermodynamics and acoustics:
Exhaust heat powers car’s air-conditioning
Time to tune up your ears and
Learn to Listen
Matt Bartlett has expanded his webpage to encompass
other DIY audio projects.
A little while back, I got curious about the hearing response of dogs, and
which gives audiograms for several different animals.
“Hey, now, what’s that sound” –
Security software recognizes the sounds of danger.
Professor J Kim Vandiver is being
honored for his service to the oil industry.
is both an excellent instructor and a valuable resource - the
award couldn’t have gone to a nicer guy.
Listen Carefully, House Hunters, and Plan Ahead:
think about noise inside the house, check the surrounding environment,
advised Savereid, who’s gotten more than one phone call from a distraught
home owner who moved in and then discovered his house was in the flight path
of an airport.”
May 03, 2005
This past weekend, I got to do something that I’ve never done before:
I recorded an organ recital performed by Dr. Leon Tilson Burrows and
Karen Whitney at Springfield’s
Old First Church. My
recording setup consisted of my Marantz PMD670 solid state recorder
and two ribbon microphones in a stereo
configuration (the microphones are not generally available yet, but
if you’re interested in them, I would suggest that you
watch this space
over the next couple of days). While I have probably made dozens (if not
hundreds) of audio recordings for noise control and diagnostic purposes, but
this is the first time I’ve attempted to make a music recording. I discussed
this effort with several friends and colleagues, many of whom shared
stories of ‘professionally-made’ recordings that did not come out well.
All-in-all, the recording came out fairly well. The biggest problem came about
because of my choice of microphone placement. If you click on the picture above,
you’ll see that the microphones are only located a few feet above the proscenium
floor. I didn’t want the microphone stands to block the line-of-sight between
the audience and the performers, so that limited my choice of mic placement.
As a result, footfalls on the stage and
on the organ pedals were audible throughout the recording.
I spent yesterday preparing a CD of the recording - the basic steps included
down-sampling from 48kHz to 44.1kHz, applying compression, applying
gain to some of the annotations, and editing ‘dead air.’ Some lessons I learned:
- As a sometime-audiophile, I’ve always advocated the practice of keeping
recordings as ‘pure’ as possible, with no compression or equalization added during
or after the fact. Turns out, compression is a necessary evil.
The dynamic range of a live performance is just too much to be useful in even
a high-end system in all but the quietest of listening rooms.
- The above observation has confirmed in my mind that more than 16 bits
of dynamic range for playback in a consumer audio system is just a waste - again,
unless you have a very quiet listening room (and like your peaks to be
extremely loud), you would never use all of the dynamic range. That said, there
is such a thing as apply
too much compression. (None of this, of
course, applies to recording and mixing, where 24 bits or more may
be necessary to properly capture and edit audio signals.)
- I performed the digital audio processing using the free, open source
audio editor running on Mac OS X. I’m a big fan of open source and free software
(my business practically runs on TeX, MySQL and GNU Octave), and I’ve found
Audacity useful for rudimentary audio editing. It’s been
that Audacity is suitable for professional audio use, and this project
gave me a chance to put it through its paces. Long-story short: Audacity is nice,
but it’s not a pro tool (pun intended). Audacity has lots of quirks, but
the bug that made be give up on it was when its “save multiple” function
(for splitting one track into separate files) placed the same audio samples at the
end of one track and at the start of the following track. Audacity is nice,
and it will get better with time, but it’s not there yet.
These are certainly not earth-shattering insights for experienced
recording engineers, but it is interesting to walk in their shoes for
ExtremeTech has published an
on THX’s approach to providing a great sounding audio system. I’m particularly
happy that both THX and the article stress the important of room acoustics
to the overall sound. My only complaints with the article are that the author
confuses resonance with modal behavior, and that he confuses the
effects of absorption and diffusion.