Cold and sound...

Posted by: EFalardeau

Cold and sound... - 12/17/09 09:20 AM

Each year, I notice the same phenomenon, but quickly forget about it, especially since I automatically put it in the "psychosomatic" category. But this year, it just hit me to post the effect and see if anyone as actual info and verify that it is caused by sensory perception.

The phenomenon is as follows: when it is cold enough outside, my iPod starts sounding better (clearer, neater, cryspier). Yesterday and Today, temperature are between -15C and -20C in Montreal and the sound change took me by surprise yet again.

So, is it due to the cold changing our (my) senses and making us (me) perceive sound differently, or is the cold changing enough the frequency response of my (our) headphones that I (we) notice a... noticeable change?
Posted by: alan

Re: Cold and sound... - 12/17/09 10:06 AM

Hi Eric,

Very cold temperatures will certainly affect the frequency response of transducers (speakers, headphones, microphones, phono cartridges) but almost always negatively, i.e. high-frequency response usually suffers. In speakers, cold will thicken the ferrofluid liquid that surrounds the voice coils and inhibit the movement of the voice coil, slowing it so it doesn't respond fast enough to high frequency movement, and the speaker will sound muffled or muted. Similar effects may occur with damping materials in microphones and cartridges, but it's odd that you find the sound from your iPod ear buds "crisper" in the cold.

I've not seen any conclusive data on the response of our eardrums to cold, other than the speed of sound changes with humidity and in the cold the air is very dry, but that still wouldn't support your experience.

Posted by: SirQuack

Re: Cold and sound... - 12/17/09 10:14 AM

Cold normally helps clear up your sinus/ear passages, my guess is your less clogged up.
Posted by: alan

Re: Cold and sound... - 12/17/09 10:17 AM

Hi again Eric,

The more I think about this, the more I believe it's a psycho-acoustic effect. Certainly when you are in very cold weather (and I recall that Montreal winters are brutally cold), you seem much more alert, keyed up. It's almost shocking when you first encounter really cold temperatures. So perhaps, as you've noted, it's simply that your senses, including hearing, are heightened.

I was thinking about ear buds or headphones: your body heat would keep them relatively warm and insulated from any termperature effects on the voice coils, so the effect you are experiencing is a heightened sensory perception. . .this would seem to be fertile ground for some post-grad student to investigate.

Posted by: EFalardeau

Re: Cold and sound... - 12/17/09 10:39 AM

Thanks. I had always dismissed this as being a perception thing, but I thought I would throw this to the forum.
I will pay attention when it gets actually cold (-15C/-20C can only be described as "somewhat colder" \:\) ), but I might be too preoccupied with survival than music...
Posted by: BlueJays1

Re: Cold and sound... - 12/17/09 11:25 AM

I agree with Alan that it is a possible combination of psycho-acoustics and actual changes occuring in the body which could possibly alter your senses.

Cold is a threat to the human body so naturally there is some natural survival insticts/changes happening and it will alter your perceptions. Under "normal cold" within the threshold I would think there would be an initial attempt by the body to send warm blood to the brain, ears, feet, hands etc. When changes are occuring in the brain, anything is possible. It is possible under your conditions it could heighten the senses. Under extreme conditions over a period of time that warm blood will get diverted to save the brain and other vital organs and the "less important" areas such as the feet, hands and ears would be sacrificed. No bloodflow or reduced bloodflow in cold equates to frostbite and lack of sensation. I guess this could be equated to the sensation of your arm "falling asleep". Sensation/perception and blood flow are definitely intertwined \:D ( I won't go there) :D.
Posted by: michael_d

Re: Cold and sound... - 12/17/09 01:02 PM

I’ve never really dug into this, but I’ve always “thought” that I could hear better when ambient air temperature is colder. Hunting first thing in the morning as the sun comes up on a cold autumn day for example. It always just seamed that I could hear things better than later in the afternoon.

But now that I’m thinking about this in response to reading the thread, I think there is some theory to support this thought. When you consider the speed of sound, it is rated at 68 deg F. The equation changes as the temperature changes or if the humidity changes. Also, sound travels faster in water than air. All this leads me to believe that a human being can hear better, or at least differently as the ambient temperature fluctuates.

I’ll be pondering this for a while……….
Posted by: jakewash

Re: Cold and sound... - 12/17/09 01:07 PM

Could it be that the closer you get to the dew point the better the sound moves through the air as it now conatins the most moisture it can hold for that given temperature? The dew point is usually achieved in the early to late evening and morning hours.
Posted by: PeterChenoweth

Re: Cold and sound... - 12/17/09 01:41 PM

Are you using the iPod outside *in* the cold? Or do you mean just *when* it's cold outside. If it's actually *in* the cold, then there could be some physical reason. Maybe a prelude to those fancy-pants liquid nitrogen treated frozen speaker wires that some purveyors sell. ;\)

But if you just mean *when* it's cold out, and you're using the iPod inside a heated space, then I think it's just in your head. Well, I guess it's all in your head, regardless. ;\)

I wouldn't think that atmospheric conditions could make a difference to the sound waves themselves in this scenario. There's just so little atmosphere between the headphones and your eardrums. And most of that distance is inside your head anyway, all of it if you're using IEM's. Whatever space the sound is traveling through is going to quickly warm to near body temp & humidity anyway.

Certainly, atmospheric conditions affect sounds over a distance. The scenario of hearing better in the woods on a cool autumn morning is likely caused by temperature differences. If there is enough of a temperature difference between the woods and the atmosphere above, or even between the spaces within the woods, sound will react to those different densities. I'd suspect that it would cause sounds to be more readily reflected around within the spaces. So like being in an echoey room, things seem louder. And later in the afternoon as the temperatures equalize, there's less of a trapping affect. Sort of like how WWII submarines would hide from destroyers under different thermal layers of the ocean.

But yes, cold definitely can mechanically affect speakers. But not in a good way, in my experience. The easiest way to observe this is in a car if it sits out in the cold. On a bitterly cold day, the speakers will often sound tinny and distorted until the car warms up a bit. It's especially noticeable with speakers that have rubber surrounds.

Randy might be on to something. The cold, dry air of winter will dry out your sinuses. And since ears are part of the whole mucus-and-earwax network in your head, it could just be that your hearing is a bit better when your head's dried out. \:\)

Interesting topic. I look forward to hearing what other's have to say about it.
Posted by: BigHonu

Re: Cold and sound... - 12/17/09 02:17 PM

Yeah, we just dipped down to about 60F (about 16C) the other morning. BRRRRRRR! \:D

I like the theory of hearing better when your head is less clogged up. I have pretty bad allergies and sinus issues, but when I was going to college in Indiana, I would LOVE the winters because I could wake up every morning without being stuffed up. Would make sense that the clearer your head is, the better your ears work.
Posted by: jakewash

Re: Cold and sound... - 12/17/09 05:06 PM

 Originally Posted By: BigHonu
Yeah, we just dipped down to about 60F (about 16C) the other morning. BRRRRRRR! \:D
And here I am excited it is 43F after a couple weeks at -22F. :P
Posted by: Adrian

Re: Cold and sound... - 12/17/09 05:18 PM

I'm not sure about how cold affects sound, but I know smells a whole lot nicer in the cold weather. Good restauranty smells, while walking on a city street in the winter time...YUMMY!!
Posted by: PeterChenoweth

Re: Cold and sound... - 12/17/09 05:32 PM

 Originally Posted By: jakewash
And here I am excited it is 43F after a couple weeks at -22F. :P

I know how that feels. It was in the mid 40's when I went to lunch today. Felt so warm compared to the single-digits and teens that we've been having (nothing like -22F...yikes), I almost put my convertible's top down. Seriously. \:\)
Posted by: jakewash

Re: Cold and sound... - 12/17/09 06:25 PM

It feels like shorts and T-shirt weather right now
Posted by: fredk

Re: Cold and sound... - 12/17/09 09:19 PM

 Originally Posted By: alan
Certainly when you are in very cold weather (and I recall that Montreal winters are brutally cold), you seem much more alert, keyed up. It's almost shocking when you first encounter really cold temperatures.

Ha! In my western winter days -15 to -20 is just cold enough to keep the tourists off the slopes and allow us locals to spend much less time in lineups. -25 was perfect for those high speed full tuck runs.

-45 is Brutally cold.
Posted by: BlueJays1

Re: Cold and sound... - 12/17/09 09:43 PM

 Originally Posted By: fredk

-45 is Brutally cold.

Just think about driving on a ice road in a big rig to Tuktoyaktuk. You sure as hell don't want a breakdown or even worse have the big rig fall through the ice \:o .
Posted by: fredk

Re: Cold and sound... - 12/17/09 10:03 PM

In the early 80s I met a guy running the Alaska Highway in the winter. With danger pay he was making around 100K. That was serious cash in those days.
Posted by: BlueJays1

Re: Cold and sound... - 12/17/09 11:37 PM

It is very lucrative. What I have seen on Ice Road Truckers on the History channel centers around exploring natural gas reserves in the North West Territories. Fascinating stuff.

Now I understand how bbigwrys can afford M80's strapped inside the big rig. \:D
Posted by: grunt

Re: Cold and sound... - 12/18/09 03:31 AM

I don’t know the physics behind it but they taught us grunts that sound carries farther, seeming louder (closer) in low temperature than warm. However I’m not sure how that would impact earbuds.
Posted by: EFalardeau

Re: Cold and sound... - 12/18/09 04:10 AM

No ear buds. Sennheiser PXC-250 + LittleDot Mk I.
Posted by: pmbuko

Re: Cold and sound... - 12/18/09 06:36 PM

Cold air is denser, so the molecules are more closely packed together. What makes it denser is that the molecules aren't moving around and bouncing into each other as much, so each molecule occupies a smaller average volume of space. Because sound is transmitted by molecules colliding into each other -- and more collisions occur in warm air than in cold air -- the speed of sound is higher in warm air than in cold air. What you learned about cold air sound wave travel in your grunthood (is that a word?) is not always true.

Sound will reflect and refract off of air temperature gradients. If the air is still sound will travel further than if the wind is blowing, not because the wind interrupts the sound wave directly, but because there are more temperature gradients between the source and the listener.

If there is a layer of air a distance above ground that is cooler than the air at ground level -- as is often the case in the afternoon -- the speed of sound decreases with height. This means that a sound wave traveling close to the ground is traveling the fastest, and the part of the wave farthest above the ground is traveling the slowest. This effect tends to pull or bend the wave upward away from the ground.

If the air is coolest at ground level and warmer layer exists above it -- as is often the case on a cold morning soon after sunrise -- sound waves would be refracted down and have a chance of bouncing back and forth between the ground and the cold layer above it to reach much further than is normally possible.