Am I going temporarily deaf in the evening?

October 4, 2013 11:35 PM

I constantly find myself turning the sound down in the morning - then turning it back up as the day goes on. It's particularly noticeable in the car: on the morning after a night out, I invariably find the volume of the radio is set way too high for my taste - even when a night out is just board games with friends instead of loud partying. Is this just confirmation bias, or some known physiological or psychological effect?
posted by Dr Dracator to Grab Bag (11 answers total)

Everything is super super sensitive when I wake up - sounds, smells, light are all tied for the worst, touch is the runner up. Things to which I am normally pretty sensitive (itches from pet dander, allergies, etc) are also unusually bad if they hit me within 10-15 minutes of waking up.

i think it is because i am bad at waking up, i like the blankies
posted by elizardbits at 11:39 PM on October 4, 2013 [5 favorites]

I don't think it's confirmation bias; I do the same thing with the car radio. Elevated sensitivity early in the day is probably part of it, but I've always attributed it to having turned up the volume so that I could hear it clearly over ambient noise. On my way home in the evening, there's likely to be a lot of vehicle-related noise -- freeway-speed wind, the engine, tires, heavy traffic, etc. and the radio gets adjusted accordingly. But in the morning when I start the car again there's none of that racket on my quiet residential street and the radio seems much louder by comparison.
posted by jon1270 at 2:59 AM on October 5, 2013 [2 favorites]

It is both a physiological and psychological effect, I think. We are are more fresh in the morning, all our senses have rested and so are more sensitive to stimuli and many of us like things to be quiet for a while. Then as the day goes on we can take a bit more volume.
On the psychological side, music is usually going to make us feel something, an emotion or a rythm or whatever, and there is a psychological term for when we perceive differences in stimuli and the differences have to be bigger and bigger before we percieve them and such, I completly forget the details and the name of this, but it exists.
posted by CrazyLemonade at 3:35 AM on October 5, 2013

I too turn the radio volume higher in the morning than evening. I think it has more to do with the volume different radio stations play at (I can tell you which of my usual half-dozen stations will be loud versus which will be quieter): the 'louder' stations simply tend to be the ones I listen to going in to work, while the 'quieter' ones are my afternoon/drive-home stations. Also, there's the ambient noise to consider: do you drive with the windows open in the morning and closed in the evening? Open windows let in a LOT of noise from wind flow and other vehicles. And how's the traffic? Perhaps you're driving through lighter traffic in the morning (fewer cars to make noise in the first place) and heavier traffic later in the day.

Or yeah, perhaps you're simply 'not really awake yet' and not paying as much attention early in the morning, and it takes a higher volume to get you to notice something on the radio!
posted by easily confused at 3:46 AM on October 5, 2013

Best answer: It is called sensory adaptation. It is normal.
posted by srboisvert at 6:37 AM on October 5, 2013

A mix of adaptation and ambient background noise probably. I'm often up and about in the wee hours of the morning and the TV set at 10 is loud and I'm worried about bothering neighbors... until a plane flies over or an 18 wheeler passes by and I can no longer even hear the TV over the noise. The TV is up to 20 or more by evening and doesn't seem too loud at all. So a mix of waking up after hours of little noise and ears are sensitive and the world is pretty quiet, by the end of the day there has been noises all day long and the world is rather loud during the daytime.
posted by zengargoyle at 10:59 AM on October 5, 2013 [1 favorite]

Do you have tinnitus? I find my tinnitus is a lot louder as the day goes on, and things that I can hear fine in the morning are almost completely drowned out by evening. Especially if I'm drinking, or particularly tired.
posted by still_wears_a_hat at 12:58 PM on October 5, 2013

Do you have seasonal allergies by any chance? My house is pretty clear of allergens, but during the day when I'm exposed to all type of pollen I get stuffy and my ears block up a bit.
posted by 26.2 at 1:59 PM on October 5, 2013

There is a super awesome biological reason for why this is normal and when I have some time tomorrow I will explain.
posted by Cygnet at 8:26 PM on October 5, 2013 [1 favorite]

Best answer: OK, so here's how your inner ears work. Inside your cochlea, tiny little "hairs" (they are not actually hairs but protrusions from the top of cells - cilia) sit in the fluid that fills the cochlea. The tips of the hairs have little teeny molecular "springs" (molecules that can stretch - tiplinks - made of ankyrin) on top of them, and the other ends of the springs are attached to the membrane of a neighboring neuron. If the tiplinks are pulled, they actually mechanically open tiny little channels on the neighboring neuron, causing an influx of ions from the outside fluid. That ionic influx triggers an action potential in that neuron, which travels (through several synapses) to the brain, and results in hearing. Each neuron responds to a different frequency of sound. How? Because the cochlea is a totally fluid-filled space, but it has a flexible membrane on one end - the ear drum. When sound hits your ear drum, waves are created in the fluid inside the cochlea, and the peaks of the waves - the places where the disturbance of the fluid is the greatest - depends on the frequency of the sound that caused the vibration. When fluid moves, the little cilia wave around in the fluid and due to their mechanical displacement from their neutral position, and this causes the tiplinks to pull on the ion channels, which causes them to open and an action potential is fired. This is a lot of information, I know. See this resource if you want to read up on it.

So, now I can tell you WHY being in a quiet environment alters your threshhold of hearing.

It's because the ion channels that are connected to the tiplinks aren't really in a fixed position. They are actually positioned by actin and myosin molecules - the same molecules that make your muscles work. (Actin is like a track, and myosin is like a little train car that can drive up and down and "anchor" itself if necessary.) Basically, in a quiet environment, your inner ear uses the actin and myosin to move the channel slightly farther away from the cilia, causing the tiplinks to be rather taut. This means that even the smallest fluid movement will cause the tiplinks to open the ion channels and a sound to be heard. When you're in a very noisy environment, the actin and myosin move the ion channels very close to the tip of the cilia, meaning that the tiplinks have to be displaced a LOT, by a really LOUD sound, in order to cause signal transduction to occur.

Feel free to ask questions if this is unclear!
posted by Cygnet at 5:40 PM on October 7, 2013 [3 favorites]

Response by poster: Thanks for all the answers - sensory adaptation is apparently a good google term for this. I had no idea there is such an adaptive mechanism for the ear - I only knew about the eyes adapting to light levels - and the way this works is indeed super awesome.
posted by Dr Dracator at 11:58 AM on October 8, 2013