[Tabascosauce]

Living in the southern hemisphere means that Xmas falls in the middle of our summer.  Xmas means heatwaves, rather than snowmen and log fires.

I have experienced a few days of 37 degree celcius maximums, and humid thunderstorms.  This, coupled with a few days off work, has got me thinking.

For all our concentration on the performance of our equipment, high end audio boils down to how well the air molecules that enter our ears can be made to vibrate.  The climate conditions must effect the density of the air molecules, and the level of water vapour mixed with the air molecules.

What noticable effect can climate conditons have on our perceptions of the sounds we listen to?

[Mad DOg]

humidity can affect the sound.

[PhilNYC]

I notice on hot summer days that the voltage in my house drops by 10-12 volts because of all the air conditioners operating in my neighborhood.  Not a climate thing directly, but definitely an effect on audio performance...

[denverdoc]

Of course the speed of sound is directly linked to the density of the atmosphere. Water vapor as in why do clouds float is less than that of the average mix of diatomic molecular N2/O2 which at 80/20 proportions and 28/32 molecular weights, is considerably heavier.(H2O=eighteen) Wet air then slows the speed of sound, and promotes deterioration of any carbon based product, save perhaps diamond and a few others. So maybe on a really foggy day, sound arrives at your ears a hundred microseconds later.  So far as i know no phase shift or scatter either as the little audio wavelengths are still gargantuan compared to molecules. No rainbows in the audio frequency range.

But at the risk of rudeness, why even ponder climactic consequences on your audio system's fidelity, when global warming (also affects the speed of sound--this is an exercise left to the reader) threatens extinction of H. sapiens.  

Wondering,
John

[Tabascosauce]

John,

Insightful reply.  I may be completely wrong, but is it a bit more than the speed of the sound entering our ears?  Top end audio is always going to sound better than average audio at the same sound speeds.  My thinking is that it is all to do with how well the molecules vibrate, based on our subjective interpretation of what our ear drums pick up.

Yes, maybe this is a folly compared to global warming, but I've read so many threads about improved power supplys and interconnects that I thought maybe this subject is worth pondering.

[Ulas]

Changes in the velocity of sound that result from climatic changes can have a profound effect on what we hear. For any given frequency, the wavelength is inversely proportional to the velocity. As a result, a room mode that may be excited by a particular frequency on a hot, dry day will not be excited on a cold damp day and vice versa. That changes the way the room interacts with the sound produced by the speakers. I think any one who uses room correction equipment should update the equalizer settings each season.

[denverdoc]

Well, perhaps you are right as to the legitimacy of your inquiry compared to many, say how much better cryogenic audio cable is to rest. My beef I guess is that so few listeners consider collisions or the smearing effect of reflected and therefore late arrivals. In other words, room treatment!

Point well taken in recent post--I remember as a researcher, certain times of the day our electrophysiology setups would become bedeviled with this ugly tri-phasic noise that would swamp the signal trying to me measured--turns out big coolers would kick in and totally corrupt the AC supply.

As to whether wet air impacts the eardrum differently, my hunch is that  the compliance of the tympanic membrane might possbly be affected more than by the small shift in rho. As you may know, the moist but hollow middle ear serves as an acoustic transformer--the thin membrane that makes up the ear drum is living tissue, but is more like skin than soft tissue and if memory serves me correctly is contiguous with more external portions of the ear. It is obviosly almost impermeable to water so that different humidity conditions likely exist between inside and outside. An ex I will try is to submerge my head and see if that silver cable does indeed make a diference, if so I might just leave it there,
J

[denverdoc]

I did some research, and discovered humidity is a neglible effect on c (less that 3m/s between 0 and 100 percent RH out of 340 so about 1 percent diff), and that it is faster in more rarefied air, contrary to my recollections about c in different materials, propogation velocity owes more to elasticity and information availability--faster moving molecules will transmit changes in pressure more rapidly than slow ones--at zero Kelvin nothing moves, obvioulsly, no propogation at all.

But there was a greater error in a recent post that suggests wavelength/frequency impacts the velocity--not so, c is the constant whether with light/em radiation or sound. So room modes do not change with humidity and only very slightly with temp.
J

[joeling39]

Hi,

I feel that climate conditions definitely affect the perceived quality of sound of my audio system. This is one of my pet hates. I have noticed that on rainy days where I live now (Malaysia), the stereo sounds a little off (dull ?). Not very sure how to describe it but I do not like it. I am not sure whether it is the humudity or the lower atmospheric pressure or maybe both.

You are lucky to live in Perth where weather is fine & beautiful almost all year round. Best time is during the autumn at night when it is cool & dry. Beautiful sound. I lived in Perth for the better part of the '90s.

The observation above is independant of power supply constraints / irregularities. I have 2 PS Audio P300 & 1 Exactpower E15A powering all components in my system & the effect of the climate is still very evident.

Regards,
Joe Ling
Malaysia

[denverdoc]

Joe Ling,

At the risk of sounding insulting, maybe your mood is more dampened by the weather than your rig. I lived in the tropics for a stretch and became more than a little depressed by the sound of water drumming the adjacent rainforest, knowing it would arrive within minutes. Obviosly there are many other variables than just eadrumsear drums and speed of sound--like paper woofers, foam surrounds, and undoped tweeters. it is puzzling so i am more curious than dismissive--like if \you were in a room underground and had no idea as to atmospheric conditions, can you detect a diference?
J

[joeling39]

Dear denverdoc,

Your comment is rather interesting as I have never thought of it like that before. However, as far as I know, having been born & bred in Malaysia & then Singapore before moving to Australia, my mood is not dampened by wet weather.

To clarify, my assumption is that the climate condition is permeated to the listening room to a certain extent (i.e. if atmospheric pressure is low, then the room will reflect the same. If exterior humidity is high, even with air conditioning, the humidity in the room will be higher than normal).

Anyway, audio as a hobby is so very subjective. The most important goal is to be satisfied with what you have or even better - to know what you want that can give satisfaction & you know how to get there or you are on the process of getting there.

Regards,
Joe Ling

[denverdoc]

Joe Ling,


On behalf of the many residents here on audio circle, please accept my condolensces for the devastation wreaked on Maylasia and throughout SE asia.
John

[joeling39]

Dear denverdoc,

Thank you for your kind words. The west coast of Penisula Malaysia is more affected but not as bad as some other countries.

I shudder to think what it would be if this occurred along the South China sea along the east coast of Peninsula Malaysia & North of the island of Borneo (East Malaysia) as I have close to 200 PAX offshore working onboard oil platforms & workboats.

Regards,
Joe Ling

[Mad DOg]

Hi,

I feel that climate conditions definitely affect the perceived quality of sound of my audio system. This is one of my pet hates. I have noticed that on rainy days where I live now (Malaysia), the stereo sounds a little off (dull ?). Not very sure how to describe it but I do not like it. I am not sure whether it is the humudity or the lower atmospheric pressure or maybe both.

You are lucky to live in Perth where weather is fine & beautiful almost all year round. Best time is during the autumn at ni ...

hello joe ling,

actually, a component designer who I greatly respect mentioned that humidity has a very real effect on sound contrary to what denverdoc has stated. in fact, he specifically mentions that gear that normally sounds brighter will sound less bright when humidity is high because of the very fact that the air is denser. this is consistent to what you are describing.

more importantly, i'm relieved to hear that you weren't affected by the catastrophe...

[denverdoc]

Mad dog,

I think you misunderstood my point. It was not that these differences in perception might not exist, only that the air density and velocity of sound changes are unlikely candidate explanations.

So Joe's and your audio designer friend's observations may be valid--but not for the reasons given by your buddy, that is higher humidity causes the air density to be higher. This is simply not the case, as I explained a few posts above--so if we want to understand this phenomenon, we need to look for other explanations. Density goes down with increasing humidity for the same reasons clouds float at altitudes ranging from a couple of thousand to tens of thousands feet high, where the air is much thinner.

[joeling39]

Hi,

As I said, audio is very subjective, I would rather not be able to hear a difference due to fluctuating weather / climate or sagging power lines but unfortunately I do.

As for the air density, I think (non scientific by the way & maybe wrong) the increased water vapour in the air has something to do with the different perception of the sound quality of my audio system. I am not ruling out lower than usual atmospheric pressure as well.

Happy & Safe New Year to all.

Regards,
Joe Ling
Malaysia

[Rob Babcock]

Wouldn't the water vapor/humidity be an equal impediment to treble & bass alike?  I don't know the science of it, but it seems to me frequency wouldn't be relevant.  But I'm not sure.

[SWG255]

I read a professional audio article concerning sound reinforcement a year or two ago that suggested increased humidity would cause high-frequency rolloff in a sound reinforcement system when providing sound amplification over a large area such as an outdoor venue. I can't remember the actual numbers cited, but the effect seemed to be measureable in distances of more than 25 feet or so. This would seem to be too small a change to be what has been noticed in your system on damp days, but then again, perhaps it's yet another of those "I can hear it but I can't measure it" phenomena in high-end audio.

[Carlman]

I think high humidity vs. low humidity has little or nothing to do with what I hear.  However, lower or higher barometric pressure definitely plays a part on what I am able to hear.  Maybe higher pressure puts more pressure on ear drums?

Also, changing weather such as a front coming through messes with my sinuses quite a bit...

[denverdoc]

One variable that has not been considered explicitly that seems to have by far the geatest relevance is absorbtion coefficient vs RH. Based on the suggestion of the last post did a quick search which shows that esp between 10 and 40 percent RH, the absorbtion coefficient increases dramatically, and whats more different freqs are affected differently--all the ingredients necessary to account for the observations reported.

I will sleep easier tonite knowing this-should a'philes invest in humidity controllers--YIKES! A whole new area of potential room treatment

To those wishing to see the technical details, check out this link:
www.rane.com/pdf/eespeed.pdf


John Smolley