Since it’s been a while, I have received approval to write about phones and scones – yummy! Oh, I misread that… I can talk about phons and sones? Oh boy. I mean… hmm… uh…
Every so often, you get exposed to a term that you’ve never heard; it seems like someone just made it up – and the more you learn about it, the more made up it seems.
(Disclaimer: I swear I didn’t make these up.)
Today, I will introduce you to two of these amazingly real terms, and do my best to explain why these terms exist… prepare to be amazed!
OK. Phons and Sones are two related terms in Psycho-acoustics that refer to how humans perceive the “LOUDNESS” of sounds. These are actual real concepts. (Stop laughing.)
Don’t we all perceive sound differently? YES!
So how can you have an actual measurement based on something that everyone perceives differently? EASY!
Take a bunch of people.
Play a 1Khz sine wave.
Play another frequency.
Ask them if it sounds just as loud.
Repeat. (No kidding.)
OK, this is over simplified… Let’s start by setting some rules that make this a little easier.
For reference – whatever dB level that 1KHz wave is will be the reference for the whole group… compare a bunch of frequencies at different levels to 1Khz at 40 dB – and we’ll call all the ones that sound just as loud the “40 PHON Equal Loudness contour.”
Why? Because they sound just as loud as the 1kHz wave at 40 dB. (I’m not joking!)
Then compare a bunch to a 1KHz wave at 50dB and call all of those that sound as loud, (wait for it)
the “50 PHON Equal Loudness contour.”
Then 60dB, 70dB, 80dB… etc (see a pattern?)
Now, plot all of these from a bunch of people who hear pretty well… take an average and WHAMMO!!!
The PHON Equal Loudness contours!
(To be fair this is the data from a bunch of 18-25 year olds who still have reasonably good hearing…)
Remember this is PERCEIVED LOUDNESS. The average of what the test subjects said “yeah, uh, that’s just as loud, Dude.”
It seems strange doesn’t it – that these aren’t nice straight lines? That’s because the human ear is constructed in such a way to be more sensitive to certain frequencies than others.
So according to this chart – a 1KHz wave at 40 dB sounds just as loud as 125 Hz at ~60dB and 3150 Hz at ~35 dB. (All on the 40 Phon contour.)
That’s Psycho-acoustics for you. (Wow.)
So if you’re an average person with average hearing, your bass perception is terrible and over 16KHz you’re basically – well… deaf.
But you hear really well from 2kHz – 5kHz!
Anyway… what’s the point?
Phons measure how loud the human ear perceives sounds at different frequencies. (TADA!)
FINE! – then what are Sones ? To make this simple – Sones are relabeled Phons.
You start with 40 Phon being 1 Sone then double it every 10 Phon.
40 Phon = 1 Sone.
50 Phon = 2 Sones.
60 Phon = 4 Sones.
70 Phon = 8 Sones.
80 Phon = 16 Sones
90 Phon = 32 Sones
100 Phon = 64 Sones
(Hmm, thought that would be more complicated? It is – but that’s basically it in a nutshell.)
You will almost never see a phon or a sone. Bathroom exhaust fans and blowers are sometimes rated in Sones – to let you know how quiet they are… The problem is that no one actually knew how quiet that was until now!
I guess it sounds better to say –
“This bathroom fan operates at only 2.5 Sones!”
…Than it would be to say…
“This bathroom fan resonates at over 80dB,
but it’s in a frequency range that humans don’t hear very well,
so it sounds quieter than it actually is… no… really!”
Human perception of sound is very important to the development of acoustic products – Psycho-acoustics are not a joke.
(Why are you still laughing?)
Acoustics First would like to wish everyone a happy holiday season, and a happy new year.
- Acoustics First Team
Airflow is good. Circulating stagnant air has many health benefits, but what do you do when that ceiling fan is just making too much noise?
To start, check all the normal suspects; is it balanced, cleaned, level, blah blah blah… You’ve probably already checked these anyway. It’s an older fan, the motor hums, because older fans hum. If it’s vibrating through the structure, there may be something you can do to isolate that extra vibration – and at least keep the other occupants happy.
When most people think of Vib-X pads, they think of a musical function; Isolate your speakers, isolate an amplifier, isolate a (insert name of miscellaneous musical gear here)… but there are some really useful everyday functions for this wonderful material. Like keeping that fan from vibrating the entire house!
The simple install may involve a contractor, or at least some one who knows electricity, so you don’t electrocute yourself… but after shutting off the power to the fan, it’s pretty quick. Take down the fan and find the box. Disconnect the box. Cut some Vib-X to separate the box from the wood. Cut some Vib-X squares to use as washers. Remount the box using the diagram, a couple fender washers, maybe a couple optional grommets if you desire – then re-install the fan.
Ceiling fans are usually mounted to an electrical junction box in the ceiling, which is usually just screwed to a ceiling joist or some simple wooden frame. By using the Vib-X to isolate the electrical box from the wood, the vibrations do not directly transfer from the fan into the structure of the house, turning that old, vibrating ceiling fan – into a breath of fresh air.
Simple. Thought so. Don’t forget to balance, level, and clean that ceiling fan while you’re doing all this. Turn that power back on and enjoy the breeze.
That’s right. Acoustics First will be unfurling some of the wrapping and exposing the newest addition to the ArtDiffusor® Family of diffusers… the Model D. Where can you see it?
September 25-26th, 2013
Walter E. Washington Convention Center, Washington DC
Acoustics First will be set up in the main exhibit hall (in Booth 507), showing off the Model D, the newest release into the ArtDiffusor® family. Come on down to see for yourself what all the noise is about – pardon the pun.
Another interesting development is the first install of Model D’s in a Broadcast studio. In a move to “liven-up” the very “dead” studio to better accommodate the live recording of in-studio musicians, WBWV 88.7 FM in Beckley, WV pointed to the New Model D as their solution.
- How diffusion works Video.
- Photo Gallery
- Early “Alien” promo video
- Model D Pattern Designer
When Pippin Barnett contacted Acoustics First about an acoustical issue he was having with a new multipurpose space that was constructed for the Sabot School, he was in desperate need of a solution. This space was needed for functions, activities, art displays, music classes, plays, and more, but was almost completely unusable due to the acoustics.
The large space was well conceived; large open floor plan, hydraulic door to open the space to the courtyard, bathrooms, storage and lots of display space for the student’s artwork and creations. The building was also efficiently constructed using SIPS (Structural Insulated Panel Systems), which created a grand open space with no support pillars. This space was ready to be used, but there was a problem – whenever they tried using the space, you couldn’t understand what anyone was saying. To say that the acoustics were “not optimal” is like saying that the destruction of the entire universe would be “inconvenient” – an incredible understatement.
Upon arrival, we took some physical measurements of the space to calculate the surface area and volume of the room, as well as got some acoustic measurements.
Whoa… Big Boom! What you are hearing is a 3+ second RT60 time; That’s more than 3 seconds of time that the sound lingers in your space at a level audible enough to interfere with other sounds.
Which is “Inconvenient,” and “Not Optimal.”
So with some magic calculations performed by Joe Horner over at the quietest office in Acoustics First,(no really – he likes it really quiet,) a solution was developed to create a space that sounded as good as it looked.
Joe prescribed 100 2′x4′ Cloudscape ceiling baffles as well as 157 sq ft of 1″ thick Sonora Wall panels to cover the solid hydraulic door – and we listen to Joe (he’s done this a lot!)
So, a short while later, the Baffles and Panels are installed and we receive an e-mail from Pippin…
“I’d say you were right on the money!”
RT60 from 3+ seconds down to right about 1 second. I’d say that’s right on the money too, Pippin!
The Sabot School regained the use of its space and everyone lived happily ever after.
I love happy endings.