FFFFT (the fast fast fast Fourier transform)

January 25th, 2012 by Martin

No, it’s not the sound of the air being let out of your tires!

Researchers at the Massachusetts Institute of Technology have just published a ground-breaking computational method for analyzing digital signals, including sounds and images.

The Fourier Transform is a way to break a complicated signal down into its most basic components, and it’s how computers manipulate things like acoustic and visual information—everything from your jpeg and mp3 files up to complicated acoustic measurement and analysis gear that consultants like ourselves use daily.

Fourier Transform

The last major improvement in the efficiency of the Fourier Transform came in the 1960s, with the advent of the “Fast” Fourier Transform (often denoted FFT).  That was a long time ago, but the FFT is still the method of choice for on-the-fly number crunching in everything from cellphones to video games to high-end audio and graphics workstations.

The new algorithm that MIT has devised (a “nearly optimal sparse Fourier transform”) is substantially faster than the FFT for a large range of realistic and useful cases—up to 10 times faster.  It isn’t hard to imagine that such a major leap in efficiency will lead to smaller, cheaper, and more powerful electronics, since the work they do under the hood just got a whole lot easier!

[via MIT News. Graphic: Christine Daniloff]

Happy new year!

January 3rd, 2012 by Martin

Everyone at lally acoustical consulting would like to wish our friends, clients, and colleagues a happy and healthy 2012! We are looking forward to a great year and hope that you are too.

 

Random order

November 15th, 2011 by Martin

Using simple, functional components like DC motors, wire, and cardboard boxes, Swiss artist Zimoun assembles building blocks of motion into massive, engrossing sonic environments. An individual motor may exhibit repetitive motion and deterministic noise, but dozens of identical systems spawn complex imagery and random sound that evoke organic phenomena from wind in the grass to running water.

Zimoun’s “Sculpting Sound” is on display through January 8 at the Ringling Museum of Art in Florida, and the artist has an upcoming solo exhibition scheduled for February 2 – March 10, 2012 at Bitforms Gallery in Chelsea.

[via It's Nice That]

What do fireworks sound like on 72nd Street?

November 8th, 2011 by Emily

Getting off the train at 72nd St, on the subway platform we heard a funny sound and wondered ‘what is that?’  Well, it turned out to be the sound of fireworks above for the kickoff of the NYC Marathon.  A cell phone microphone does not completely do this justice but you can hear the reflections of sound off of the building facades and the overall reverberation somewhat.

Telecool

October 25th, 2011 by Martin

HEARING LOOP INSTALLEDThis week the New York Times brings a promising update on the increasing adoption of the telecoil, a technology that promises to make life much easier for those with hearing impairments.  A hearing aid or cochlear implant that includes a telecoil can directly pick up the audio from a sound system, whether for a theater or a school or even a subway booth clerk’s microphone.  The signal is beamed to the telecoil via an audio induction loop of wire permanently installed in the floor; when the listener’s hearing device is trained on this signal, it eliminates the extraneous background noise and reverberation that can make intelligible listening a challenge even with a modern hearing aid.  The listener has effectively “plugged in” directly into the source—and without the social stigma that can hinder adoption of more obtrusive external listening devices.

The concept has been around for decades and is widely adopted in parts of Europe—there is a telecoil transmitter in the back seat of every London taxi—but it is only recently gaining a foothold in the US.  With the greying of the population and the fact that more than 30% of people over the age of 65 are affected by hearing loss, the ability to make clean audio directly accessible to the ear holds “clear” potential!

Building Design + Construction Magazine – Enhanced Acoustical Design

September 27th, 2011 by Emily

Just in case you missed the August issue of Building Design + Construction Magazine, there was a very interesting article on Enhanced Acoustical Design on page 45.  Truth be told we may be a bit biased as we helped with the article – but you can earn AIA/CES credit for reading it too!

Building Design + Construction Enhanced Acoustical Design