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MagLev Trains Annoyingly Loud
crem_d_genes writes "You might hear that whistle blowing from that train coming 'round the bend, but tapes of the sounds produced by magnetically levitated and normal trains produced a result that was something of a surprise: Most people rated maglev trains as more disturbing than standard intercity trains. It had been previously known that the two types were about equally loud, but this study analyzed people's reactions to them. Since the effects on the environment will be part of the feasibilty studies for future development, acoustical engineers will have some new challenges. Some participants in the study said the sound made them 'feel insecure, some found it startling, and disliked the occasional shrill sound the maglevs produced.' The researcher postulated that unfamiliarity with the noise might be part of the problem."
I dunno ... you tend to feel louder high pitched sounds in your ears, whereas the lower ones you might feel more in your body.
The low sounds you can't "hear" are probably outside of your range of hearing. This is why you feel them instead. Sort of like a deaf person. They can feel the vibrations from music, but they can't hear the music.
What?
"MagLev Trains Annoyingly Delayed"
Most of the articles I see about these (many of them here) are about how the projects are being cancelled, or there are problems that keep holding them back.
Like the noise issue. Current trains make a lot of noise... is this noise so bad that it outweighs the benefits of a MagLev?
The article was very skimpy on the details. Where were these tests done. How many people were tested. What kind of noise was it? There is noise pollution everywhere now-a-days. So, even if this comes as a surprise, trains are a great means of transportation, and seeing that the maglev is fast, there have to be more tests done before anything is concluded.
<sarcasm>
Wonderful approach! Ignore it and maybe the problem will go away. Why would you actually want to try to eliminate the source of the noise?
</sarcasm>
If they polled people living in a city with a lot of commuter trains, then these people might rate the mag-lev more annoying than the conventional trains that they are already accustomed to.
If they polled people living in an area without any trains and the people weren't used to conventional train sounds, perhaps they would rate the sounds of mag-lev's and conventional trains equally annoying or more close to equally annoying than the previous group.
Characterizing the difference between these two group may help identify how much of the results of this poll are due to people not liking the idea or sound of any trains near them and how much of the dislike is specifically due to the sound of mag-lev trains.
Additionally, I think that the results would be significantly different for those that may live in cities that would benefit from mag-lev's and those that live in small towns that high speed mag-levs may pass through without stopping (One may have a more negative opinion about the sound of a mag-lev if the sound does not have any associated benefit for the individual)
Perhaps the most impartial group to sample would be a group in a city with no trains and no plans to get a mag-lev in the future . . . but then who really cares about these people anyway (with respect to the sound of a mag-lev that they will never have to deal with on a regular basis)?
Unfortunately this article, like so many others, draws conclusions from the data without giving the reader enough information to draw his or her own conclusions or even agree or disagree with the author.
the guy instead of actually asking people who live near a maglev/ordinary tracks what they thought
he played recordings and then asked subjects (presumably in his lab) which they disliked the most ?
anyone who lives near a train laine can attest comparing the real thing (and all its physical vibration) to one of a recording played through a 100w labs hifi is laughable, really. if he had about a 50k rig he might get close to the physical vibration and noise factor , ever notice anything is annoying if its not reproduced correctly ?
Then we ask what clips did he play ? a selection ? random ? how many in the collection ? distance away from the mic ? frequency captured ? (20-20 aint enough)
lots of questions but simply playing a recording and saying yes or know doesnt really constitute much of a study
I think the reason why people might be annoyed by the sounds of a maglev passing by is the fact that at the type of speeds maglevs operate (350 km/h to 500 km/h), the noise is NOT caused by physical contact with the overhead wiring and the steel wheel/steel rail contact but the aerodynamic noise caused by the shape of the maglev train itself. This means they'll need to computational fluid dynamics research into reducing the noise footprint of a maglev train.
Indeed, this was a major issue with the upcoming Airbus A380 super-jumbo airliner; they had to go to single-piece moving surfaces on the wings instead of louver-type moving surfaces found on the Boeing 747 because the louver-type moving surfaces generated quite a lot of aerodynamic noise above 320 km/h flight speeds.
Once I'd seen what they were capable of (you'll have to imagine a hundred 20mm rounds per second hitting a soldier; I'm intentionally not seeking a link), that sound took on a whole new meaning.
There's a whole ethical debate on this sort of imagery: can national security be weakened by US citizens being repulsed by the carnage our weaponry is capable of? Imagery impacted US public perceptions of the war in Viet Nam, and we've advanced a lot technologically since then.
I realize I'm off topic by here, but whining about maglev (pun intended) seems silly in comparison. As with jets and computer fans and traffic noise, maglev's purpose is considerably more benign. We can work around or get used to the sound.
Where would the average (e.g.) American have learned to fear the sound of a Huey? A Pavlovian response is a learned response; I don't think most people associate the sound of a helicopter with imminent death.
"Destroy science and religion. Science would re-emerge exactly the same; but not religion." - Penn Jillette, paraphrased