Jᴀᴄᴜʀᴜᴛᴜ - Tʜᴇ Cᴀsᴛ Oᴜᴛ

Anybody heard of biomimetics? This is a really nice example of it:

http://today.msnbc.msn.com/id/31172567/

Kewl.

Interesting if a tad misleading in it's opening.

"The human ear is a very good spectrum analyzer," said Rahul Sarpekhkar, a professor at MIT...

Surely it's the noodle that's the analyzer.

They vastly fucked up the human hearing range in the article, they said 100hz to 10,000hz, wheras most people start their lives with more like 20hz (several octaves below what the article states) to 20,000 (on octave above what the article states), and proceed to loose general amplitude in the high to mid frequencies from there on.

That said, this is a somewhat nifty antennae, but it seems to me it's not much more than an array of very simple antennaes tht are each tuned to a specific bandwidth, smart but simple.

The audible range and inteligible ranges are very different.

Freakzilla wrote:The audible range and inteligible ranges are very different.

Depends on the listener, both in regards to the overall health of their ears, as well as their critical listening abilities. Besides, they very much made 100hz to 10,000hz out to be the complete human hearing range in the article, which is off by entire octaves, hardly a small discrepancy.

I can hear very clearly down to about 25hz, below that it gets a bit tough to discern specific frequencies, and I'm not sure exactly where my ability to distinguish high frequencies fails - but I can say with total certainty that I can tell 15 or 16 khz clearly apart from the 10khz that the article mentioned (though I may well fail to tell 18,000 from 17,000, that's only a difference of a single semi-tone or so, and very close to the edge of my perception).

I'm allowed to split hairs when people write articles about science and then proceed to fuck up the science!

Inteligibility depends on many factors, including the surface finishes of the room they're in, the sound pressure level, etc...

Yes, the human ear can hear a much broader range than you quoted from them but what is the point of this device?

Is it to give them bionic dog-ears? Or to allow them to hear and understand a human voice?

If it's to understand voice, that entire range is not necessary and if used can actually decrease inteligibility.

Freakzilla wrote:Inteligibility depends on many factors, including the surface finishes of the room they're in, the sound pressure level, etc...

Yes, the human ear can hear a much broader range than you quoted from them but what is the point of this device?

Is it to give them bionic dog-ears? Or to allow them to hear and understand a human voice?

If it's to understand voice, that entire range is not necessary and if used can actually decrease inteligibility.

Of course for human speach intelligibility only a very narrow band in the mid range is necessary, and of course room reflections will slur transients and cause peaks and dips in the frequency spectrum. I think we both know what we're talking about on this one, I'm a sound engineer and I know you know what you're talking about!

This device in the article has nothing to do with hearing sound - it is a radio antennea that can hear and seperate many frequencies at once, which is why they compare it to the human ear (plus the cochlea was the inspiration).

A Thing of Eternity wrote:

Freakzilla wrote:Inteligibility depends on many factors, including the surface finishes of the room they're in, the sound pressure level, etc...

Yes, the human ear can hear a much broader range than you quoted from them but what is the point of this device?

Is it to give them bionic dog-ears? Or to allow them to hear and understand a human voice?

If it's to understand voice, that entire range is not necessary and if used can actually decrease inteligibility.

Of course for human speach intelligibility only a very narrow band in the mid range is necessary, and of course room reflections will slur transients and cause peaks and dips in the frequency spectrum. I think we both know what we're talking about on this one, I'm a sound engineer and I know you know what you're talking about!

This device in the article has nothing to do with hearing sound - it is a radio antennea that can hear and seperate many frequencies at once, which is why they compare it to the human ear (plus the cochlea was the inspiration).

Ohhh.... I see. For some reason I couldn't see the link here at work. I wouldn't doubt it's ability to seperate frequencies better, people have a hard time with that. Especially people who have ridden in tanks and fired machine guns.

I went to a Mass Notification (Weather, Chemical, Terror/Gunman, etc...) seminar this morning and inteligibility (speakers with voice instead of a horn or bell) is one of the things they (code officials, engineers, etc...) are pushing. That has been the trend with Fire Alarms for quite some time. Due to the durability of existing FA products, they are trying to integrate the mass notification. My office recently purchased an "intelligibility meter". A few years back I would never have believed in such a thing.

The Marriot served up a damned fine breakfast, by the way!

They introduced a "Giant Voice" system for outdoor notification that runs up to 3200 W of speakers on 200 mA from DC batteries! It only uses AC power to charge the batteries, which can also be charged by a solar panel. Most impressive. I think it's magic.

Freakzilla wrote:

A Thing of Eternity wrote:

Freakzilla wrote:Inteligibility depends on many factors, including the surface finishes of the room they're in, the sound pressure level, etc...

Yes, the human ear can hear a much broader range than you quoted from them but what is the point of this device?

Is it to give them bionic dog-ears? Or to allow them to hear and understand a human voice?

If it's to understand voice, that entire range is not necessary and if used can actually decrease inteligibility.

Of course for human speach intelligibility only a very narrow band in the mid range is necessary, and of course room reflections will slur transients and cause peaks and dips in the frequency spectrum. I think we both know what we're talking about on this one, I'm a sound engineer and I know you know what you're talking about!

This device in the article has nothing to do with hearing sound - it is a radio antennea that can hear and seperate many frequencies at once, which is why they compare it to the human ear (plus the cochlea was the inspiration).

Ohhh.... I see. For some reason I couldn't see the link here at work. I wouldn't doubt it's ability to seperate frequencies better, people have a hard time with that. Especially people who have ridden in tanks and fired machine guns.

I went to a Mass Notification (Weather, Chemical, Terror/Gunman, etc...) seminar this morning and inteligibility (speakers with voice instead of a horn or bell) is one of the things they (code officials, engineers, etc...) are pushing. That has been the trend with Fire Alarms for quite some time. Due to the durability of existing FA products, they are trying to integrate the mass notification. My office recently purchased an "intelligibility meter". A few years back I would never have believed in such a thing.

The Marriot served up a damned fine breakfast, by the way!

They introduced a "Giant Voice" system for outdoor notification that runs up to 3200 W of speakers on 200 mA from DC batteries! It only uses AC power to charge the batteries, which can also be charged by a solar panel. Most impressive. I think it's magic.

Cool. I know most intercoms and such are specifically designed to sound like shite (all high-mids, no real lows or treble) in order to absolutely maximize intelligibility. I've never heard of an intelligibility metre, I would assume it's a spectrum/envelope analyser that measures frequency content (more mids=more clearity) and attack to sustain ratios (more attack=clearer consonants)... I would assume anyways, not that I really know how such a device would work. Does it come with any explanation of what it is measuring?

http://www.gold-line.com/dsp2.htm" onclick="window.open(this.href);return false;


"The STI-PA test signal contains known modulation rates and by measuring the difference in the
sound heard from the known sound played, we can derive the STI number."

It comes with a CD that you play through the system speakers and it compares what it hears to what it is supposed to sound like.

I think it even has a cigar lighter.

Freakzilla wrote:http://www.gold-line.com/dsp2.htm


"The STI-PA test signal contains known modulation rates and by measuring the difference in the
sound heard from the known sound played, we can derive the STI number."

It comes with a CD that you play through the system speakers and it compares what it hears to what it is supposed to sound like.

I think it even has a cigar lighter.

Oh okay, this is actually much simpler than I thought. I was imagining something that measured the frequency content and envelope of "whatever" audio to determine how intelligible the sound is. What you're describing here is something we use in live audio and recording all the time, it's called "pinking" - you play "pink noise" which is just a crazy mix of frequencies, sounds like static on the TV, through your sound system, then a high qaulity mic and analysis software to tell how much damage your sound system/room is doing to the audio. Sometimes something other than pink noise is used, like crazy whale sounds and sweeping frequencies etc.

I understand now.

The signal on this thing sounds like whale songs, but not as nice.

The old requirement for Fire Alarm was just a SPL measurement to make sure it is a certain amount above ambient noise.

You have to understand, you probably design for quality whereas I usually design to meet the minimum code requirement.

9/11 has shaken my industry from the ground up.

Freakzilla wrote:The signal on this thing sounds like whale songs, but not as nice.

The old requirement for Fire Alarm was just a SPL measurement to make sure it is a certain amount above ambient noise.

You have to understand, you probably design for quality whereas I usually design to meet the minimum code requirement.

9/11 has shaken my industry from the ground up.

Oh of course, I try to make things sound nice/accurate - you have to make sure people can understand the voice yelling "your building is on fire! get the fuck out!!!".

9/11 has probably made your industry very busy, and yes, very picky. Was there a huge surge after the attacks?

A Thing of Eternity wrote:9/11 has probably made your industry very busy, and yes, very picky. Was there a huge surge after the attacks?

Fire alarms are required by law so it's a steady business... as steady as construction and remodeling that is.

But 9/11 has driven a lot of changes to the fire codes that are just begining to be published. Fire Marshals are getting tougher on inspections as are engineers on plan reviews. There are new products as solutions to the new code requirements...

It never ends.

I'm not trying to be ignorant or insensitive or anything, but how does 9/11, a terrorist attack, influence fire alarms? I don't think an advanced fire alarm regulation would have saved many people...

SadisticCynic wrote:I'm not trying to be ignorant or insensitive or anything, but how does 9/11, a terrorist attack, influence fire alarms? I don't think an advanced fire alarm regulation would have saved many people...

I think it relates more from the fires of the Twin Towers and how many technical aspects (Freak can cover that) have evolved since then...

SadisticCynic wrote:I'm not trying to be ignorant or insensitive or anything, but how does 9/11, a terrorist attack, influence fire alarms? I don't think an advanced fire alarm regulation would have saved many people...

One of the speakers at the seminar I went to earlier this week was Fire Commissioner durring the 9/11 attacks.

Fire Alarms are not only to evacuate, they also assist the first responders in communication.

As part of the evacuation plan, which is usually coordinated between the owner, designer and fire department, for the twin towers, the people in the second tower were stopped from evacuating and told to go back to their offices.

Several hundred people died because of that.

A major change that has taken place is that Mass (Emergency) Notification now takes precidence over Fire. Up until lately, Fire has always trumped everything else.

If you recall, not too long ago at a high school, someone pulled a fire station causing a false alarm then proceeded to snipe people as they evacuated from the woods nearby. Another example of when MNS should overide FA.

Interesting...
Thanks Freak. (Didn't hear about the high school incident; sounds quite scary actually)

By the way, I don't live in America, which is perhaps why some of this I don't hear about.