> and opened the decibel meter on my iPhone
These are notoriously inaccurate. To get accurate decibel readings, the mic must be calibrated to absolute known levels (something your App can't do). The App's are basically just comparing relative sounds (this sound is more prominent than this other one, and therefore must be louder... after establishing some relative baseline). Real decibel measuring equipment is very expensive and requires re-calibration routinely. So, measuring 80db could easily be in a swing of +/- 10db's (or more).
> 150dB: Jet take-off at 25 meters (eardrum rupture)
That's not quite accurate. Long term exposure could lead to damage over time, but for comparison a shotgun is typically measured at 165db when it's up against your shoulder and face. Yes, you wear hearing protection (nick-named "ears" if you are a frequent shooter) but your eardrumps aren't rupturing immediately if you take them off.
> What shocked me was the volume of the PA system
Yes, it's loud -- by design. The PA system is not there just to provide something to listen to in case you are bored. In a best case scenario, it's there for the usual "buckle-up" talk and for the pilot to give a greeting. In the worst case scenario, it's there for emergency instructions (a time when panic and passenger noises are likely to get quite loud on their own).
Actually, if you pick the correct app they are surprisingly accurate: http://scitation.aip.org/content/asa/journal/jasa/135/4/10.1...
Having done sound testing extensively, you can be sure in an airplane positioning and sound source and sound type can drastically impact your measurements. Multiple reflections can re-enforce, or reduce the measured level. The type of sound measured is very important as well.
He's not measuring pink noise on the airplane, what the measured level of a particular sound is, needs to be normalized to really understand what effects it will have on you.
I'm sure in a good test setup the smartphone can get you pretty darned close. I'm more concerned with this guy's test setup than the equipment used.
> for A-weighted sound level measurements three apps had mean differences within ± 2dBA of the reference measurements. For un-weighted sound level measurements three apps had mean differences within the ± 2 dB of the reference measurement. Since national standards and occupational guidelines specify that type 2 sound measurement instruments have an accuracy of ± 2dBA, some of the above-mentioned apps could potentially be used in the occupational setting
http://blogs.cdc.gov/niosh-science-blog/2014/04/09/sound-app...
To put it in numbers: ±3dB is doubling/halving of Power, but humans typically perceive a change of ±10dB as doubling/halving of "Volume". Also the damaging effects of noise typically scale as double-the-power, half-the time.
And personally I'd rather not be in the situation where I'd ponder if the damage to my hearing is double or half what it should be if my iPhone app were accurate: I'd rather have it show numbers that are 20dB below this level, so that I can be assured of no significant damage at all!
Side note: I'm always curious how soldiers/SWAT/HRT/etc. are able to hold normal volume conversations. If they're wearing ear-protection, how do they listen for potential threats and assailants? If not, how do they not shout all day long every day?
The technology would be similar to that used in hearing aids and noise-cancelling headphones. But it is also probably an order of magnitude or two more expensive just because the primary customers are tax-funded.
Without electronics, I could also conceive of an earplug with a winding channel bored through it, past flaps that can block the channel by moving too far in either direction and forming a seal with the outer wall of the channel. Sound energy above a certain level would push the flaps closed as the air vibrated, and would thus attenuate louder sounds to a greater extent than quieter ones. If the flaps were tuned to different sound energies, the loudest sounds would push closed the most flaps.
That would require some precise machining to fit inside the outer ear canal. The electronic filter might actually be cheaper.
You can achieve reasonable short-term protection by holding your hands flat over your ears. It doesn't reduce the subjective volume, but it does [anecdotally] prevent subsequent symptoms that indicate temporary or long-term damage has occurred.
My biggest question is how much training airlines give pilots about exactly what to say on these updates - on a recent flight, the pilot said that a critical system in the plane went from "too broken to take off" to "yep, that looks fine" with a couple of restarts just before we left the gate. I'm sure he did everything per spec, but I'm not sure how helpful it is to tell everyone that they are riding on equipment that's only legal because the turn-it-off-and-on-again principle isn't just for IT.
Yeah, but there's no reason for the people operating the PA to blast our ears for mundane drivel. I was on a flight last weekend where, because I was right next to a speaker, I had to cover my ears for 5 minutes while the flight attendant droned on about non-emergency stuff. It was so loud it hurt my ears. I already have tinnitus, so I don't need any more hearing loss.
however, in the absence of anything else it is an indication.
The number it assigns it might as well of been made up... or put on some App-specific scale like 1-10, 10 being "we think this is really loud".
Just another instance of outrageously bad customer service in the airline industry. I'm convinced at this point that they simply despise their entire customer base.
Then turn the airplane's volume to max and adjust your inline volume to a comfortable level. In my experience, the announcements will then also be at a comfortable level.
I dozed off with my headphones plugged in, listening to something relaxing on a low volume. Several times I was awakened without warning when they showed the film trailer at full volume. Boy did that piss me off.
[1] http://www.nytimes.com/2009/12/21/business/media/21adco.html
This works because most aircraft systems deliver PA announcements at a pre-set volume and isn't affected by the entertainment volume.
(The other thing I tend to do is simply disconnect my QC15 during announcements and listen (or not) to the announcement broadcast in the cabin, attenuated by the headphone's noise cancellation.)
I do like the headphone-level filtering idea, though, and might look into this for my traveling needs.
As an explanation: A compressor/limiter is a device in audio processing used for leveling (compressing) the dynamic range, by making quiet things louder, and making louder things quieter. In the extreme case, one can configure a threshold of (power, loudness, amplitude, depending on the operation of the devices) which cannot be exceeded. [All you sound engineers, please excuse the simplification...]
[1]: http://www.amazon.com/Kidz-Gear-Volume-Limit-Cable/dp/B005UH...
– Sideshow Bob
Having seen the airline industry change over the course of 30 years, I simply despise the customer base as well, and fly as infrequently as possible.
Anyone know?
I can't say that the sibling comments are wrong, but I don't think that's the real reason. Bars (clubs, really) do it because it fosters a feeling of unreality. It makes being at the bar different, and you feel different, and it's (supposed) to be special - it's a party. People show up because it does not feel like normal life.
Personally, the practice drives me crazy. As I intimated above, bars that do this are really clubs at night. I prefer places where a group of people can sit around a table and actually talk over some drinks.
As it was my party I told him to do it as he saw fit and indeed almost all the people (200) danced.
Then one neighbour complained and he lowered the volume (just for a while ;) ) and most people stopped dancing almost immediately. When he boosted the volume again, they all jumped to dance.
It was amazing.
Edit: Typo.
Reply to the comment below: I understand your comment, but the party was in a former s.XIX coastal battery fortress,(now an environmental Hotel). This fortress is excavated on the stone , below the ground level (You don´t see it till you are literally falling in the ditch). The place where the Party took place was 10 meters below the ground level, behind a fortress wall, a 6m high ditch and 1.5 km away from the nearest buildings, separated by rolling hills and Mediterranean woods.
No, sorry but I certainly was not that worried of the volume and the neighbours.
For a second there I thought that was one hell of a typo but I found out that "s. XIX" is the Spanish way to write "19th century". "Siglo" is another word for century. Now I'm wondering... why? And why use Roman numerals? Was this originally a Catholic thing?
Please could you tell the place? Menorca by chance?
I love small venues, but I hate how bad the music sounds at so many of them. Does anyone actually prefer this?
If stage volume is loud, the sound guy is likely going to push the volume even louder, both so that he has some level of control over it, and because sound coming off the mains is going to sound a lot clearer than if you're hearing everything off the stage monitors and then reflected off the back wall (yes, even if that means things are louder, they can still be clearer).
- The people deciding already have significant hearing loss and don't realize
- People who are into venue sound stuff tend to like music very very loud
- The majority of customers are actually relieved not to have the burden of needing to carry on a conversation (b/c doing so is impossible).
Not sure which of the above it is. A similar mystery is why it's considered OK for motorcycles to be extremely loud, even with modified mufflers designed to make them louder. I don't buy the safety argument, since the same could apply to any motor vehicle or pedestrian.
I'm going to go with the roadie who did the sound check is hard of hearing through standing next to big speakers and using loud music on in-ear phones; they set the level and then boost it to allow for the crowd.
Some people don't like to listen to music they like to feel it - if it's not giving you the disturbing feeling you're having palpitations then it's not loud enough! Discos for the deaf are like this apparently.
You reduce the numbers of chairs and tables. That means that you fit more people in and they have to hold their drinks. Holding a drink means you drink it quicker. They turn up the volume so you chat less, which also means you drink faster.
If bars wanted to sell more drinks, they would have more bartenders to reduce the wait times.
It allows you to be in a social setting while keeping your conversation private.
Table G-16 - Permissible Noise Exposures
https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_tab...
http://www.sengpielaudio.com/PermissibleExposureTime.htm
I think the 99dB value the author of the article measured is not arbitrary - and was chosen specifically to meet some regulations.
I see a lawsuit or a public shame campaign as far more effective. How does "United caused my child to have brain damage due to the loud PA system ... oh, and now he's autistic too"? That should work.
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Earplugs! I bought a box of foam earplugs that has supplied me for years now. I cut them in half; half an earplug is the perfect length for unobtrusive everyday wear.
I have quantities of half-earplugs stashed in all my pants pockets, in my car, my work bag, and in a little container on my keychain. I wear them in the car, on planes, at the shooting range, when grinding coffee, and especially when putting away dishes. Fucking clanging-together dishes are the loudest things I encounter in my regular routine.
For my kids I bought silicone putty plugs. They work perfectly for little ears, and I keep them with the foam plugs. My kids know where the big orange jar of earplugs is, and they've acquired some of my discipline.
I also recommend earphones (in ear headphones). They're much like earbuds with foam earplugs. They block out sound about as well as foam earplugs but with the bonus of being able to listen to audio.
Hopefully not while driving though :)
I'll hazard a guess--and I might be completely wrong--that there is some sort of legal reason for this. Maybe there have been lawsuits in which people claimed not to have heard the in-flight announcements, and therefore, did not feel not bound to them. I dunno. It just seems as if there's a reason for this. Not necessarily a good reason, but a reason.
Anyhow, this is 100% armchair speculation. It just seems like the sort of thing that could have happened.
The PA system should be reserved for actual important safety-related announcements. It's outrageous that the same system that would be used to tell you to brace for a crash is also used to repeatedly flog credit cards, duty-free sales, and other such nonsense, training everybody to ignore it.
Yes, because in a real emergency (plane going down) we need the FAs spending the precious few seconds we have going up and down the cabin telling prats to take their headphones off and listen up...
I haven't used it on flights yet but did some research and splurged on the Faber Acoustical SoundMeter (https://itunes.apple.com/us/app/soundmeter/id287615105?mt=8&...). I bought it since I live on a busy road and lots of sirens go by, adding to the general traffic whooshing. Sirens are in the high range and go over 100. Its a good app to have to check whether I'm going crazy or if it is really loud in place where I'm feeling overwhelmed with sound.
I will be sure to try it out next time I fly and provide some data. Maybe we can crowdsource samples of airline loudness.
It's a neat problem. You can turn on smartphone microphones and listen for noise levels to measure for noise pollution and law violations, etc. However, you have to develop algorithms that filter our human conversations (for this application linked above), and the privacy implications are astronomical.
Edit: http://www.citylab.com/tech/2013/05/crowdsourcing-citys-quie...
disclosure: I'm a founder
http://en.wikipedia.org/wiki/Voiceband
It may also be a legacy system using old worn-out looping casette tapes for the music.
The PA system in the airplane is part of the safety equipment, the crew uses it to inform the passengers during an emergency what they should do to prepare. Everyone knows that during a flight people will have noise cancelling earphones on and possibly dual layers of protection. Also the ambient noise in an aircraft with its nose pitched down at a steep angle or in an uncontrolled spin is likely to be quite high. The PA has to cut through all of that in order to communicate with you.
I agree it would be nice if they didn't use full emergency power during non-essential communication, but the FAA considers the safety briefing to be essential communication so you are out of luck there.
1) Kids need to be chewing something, or sucking on a nipple/bottle/straw to help facilitate inner-ear pressure changes. Most aren't, and those that can't say "my ears hurt" simply scream.
2) Kids who are tired (because they're kids or because their parents figured "I'll tire him out so he sleeps on the flight") and get startled by a scary loud voice saying things they don't understand. Like yours - probably a tuckered out toddler desperate to rest, no?
(Edited to avoid sounding like I was disagreeing with parent comment)
Has the author tried asking the flight attendants to turn the volume down?
Most of the time I'm not even playing music, but people assume so and will interrupt you a bit less often. Also helpful when making calls, etc.
In my opinion, the less that is broadcast over the PA the better.
Pretty much everyone in food service in the US exposes themselves to dangerous audio levels throughout their work shifts. My coworkers with SPL meters routinely measured sound pressure levels above 105 dB for hours at a time. But try wearing earplugs as a waiter or bartender... you will be treated like a lunatic.
I get cranky when I see kids without ear protection, especially toddlers and younger, who have no control or way to escape.
I make a point of praising the parents who put ear muffs on their infants.
United is particularly bad about cranking their PA system up into distortion screeching range. It's pure sadism.
Everything else was terrible.
There are also much more expensive concert earplugs for musicians, which do an even better job at preserving the spectrum, but I'm not that picky.
They're cheap and come in packs of 20. So I stash a handful in various places so I always have some accessible. In particular I keep a few in my essential medicine bottles since I'll have those while traveling. I find I can reuse them a few times, but if they feel off or dirty the cheapness means I don't hesitate grabbing a new pair.
The one thing I like about them over the similar Etymotics is they don't stick out of your ear quite as much.
If people would actually pay attention to a safety briefing instead of playing with their gadgets / not taking off their headphones, then the flight crew wouldn't be trying so hard to get the attention of the passengers.
With this unpopular opinion, I'll see myself out the nearest exit, which is actually located behind me.
I suppose it's possible that they fly places that have such a strong smoking culture that this is an important and useful reminder, but that seems doubtful.
Which makes me call into question the rest of the announcements.
Though, I've found United's new safety video to be so well done, I watch it every time despite having seen it dozens of times already.
Don't fault the airlines for complying with the law.
But yeah, fligh companies do not think they are important enough to bother their customers over them. They do the bare minimum required, and if you don't want to pay attention, they don't care.
