Ask MetaFilter questions tagged with frequency

Cockadoodle STFU!

@homer — Mon, 20 Jul 2009 05:13:43 -0800

I need some earplugs to block out rooster crows while I sleep. Help! The neighbors a couple houses over decided it would be just dandy to have a rooster. The damn thing crows day and night. I did talk to the neighbors and they don't care. They got the rooster to have fresh eggs. Yeah, dumb as a box of rocks.

What kind of earplugs would block out the crows? I've tried the orange foam plugs fom Walgreens and some 3M earplugs that looked the same and worked about as well which is to say not very. While low frequency sound is blocked the high frequency stuff comes through pretty loud and clear. Clear enough that I wish Hawkeye was here with his powers of persuasion.

Does anyone have any earplug recommendations so I can sleep again?

The voice of me.

cmoj — Tue, 21 Apr 2009 15:07:26 -0800

I want to produce a continuous synth tone from a sample of my own voice. Spelled out more:
I want to take a sample of my own voice and make it so that I can play a continuous tone at whatever note I wish. Ultimately, I will have several entire audio CDs, each with one continuous tone that takes up the whole CD.

So 1. How to make my voice continuous. Can this be done with software, or should I manually stretch or copy the longest, most constant section of my voice (humming a tone I guess)?
2. How to modulate it to specific frequencies?

I have OSX and Garage Band, but pretty much all I can do is record stuff with it. Otherwise, I mess with settings aimlessly. The tools for this would preferably be free, if I don't have them already.

Also, I see another AskMe that's sort of similar, and mkight help, but this is more specific.

Health effects of very light cigarette smoking over the long term

Simon Barclay — Mon, 16 Mar 2009 08:12:09 -0800

What are the health effects of very light cigarette smoking (1-3 per week) over the long term? The highly dangerous effects of cigarette smoking are well known, however (from my understanding) this is based on studies that have considered the difference between non-smokers and 1+ pack/day smokers.

So, what are the health effects of very light cigarette smoking? Define very light as being 1-3 cigarettes per week, perhaps less.

Are the effects at that dosage negligible or almost the same? Obviously I would expect it to be somewhere in between, but are there any studies that demonstrate this? One might expect that the effect of smoking is exponential, and there is a tipping point where the impact starts becoming much more pronounced with additional use. Or, one might expect that any exposure is detrimental.

I've googled it using the search terms that I could think of, but found nothing. Can anyone point to any research on this topic?

Anecdotal evidence, although interesting, would probably not be helpful in this circumstance.

What is the word frequency distribution in the NY Times?

stevekinney — Thu, 22 Jan 2009 11:22:41 -0800

How many different words (excluding proper nouns) appear in the New York Times on average? I remember hearing this friendly fact at one point, but I can't find it anywhere on Google or MeFi. It was something along the lines of "300 words make up 80% of the New York Times." Does anyone have the actual frequency off-hand?

Looking for a compact Chinese character frequency chart with English pronunciation key for Cantonese.

querty — Mon, 05 Jan 2009 01:19:58 -0800

Looking for a compact Chinese character frequency chart with English pronunciation key for Cantonese. Just watched Tim Ferriss's presentation here: http://fora.tv/2008/12/12/Feel_Like_the_Incredible_Hulk_with_Tim_Ferriss.

He mentions that he used a most frequently used character chart while learning Japanese. The chart was fairly compact and was useful for traveling. I'm looking for something similar for Chinese but also needs English pronunciation key for Cantonese. Is there something like this I can buy/download? I've found most frequently used Chinese characters lists but they're in CSV files and don't have pronunciation keys or they're in Mandarin.

I can haz sexzy t1m3? Wiz scaredz of s3x catz?

Anonymous — Tue, 30 Dec 2008 12:46:13 -0800

Okcupid.com: she's "less desiring of sex". I'm "more desiring of sex". Should I avoid? She's cute. Slightly NSFW details inside, if your boss is reading over your shoulder. I'm somewhat obsessed with Okcupid.com. Recently a woman who would seem in all respects to be a cute, healthy person that, all things being equal, I'd like to date wrote to me. She was awarded the "less desiring of sex" medallion. We've emailed back and forth a bit.

I'm a 33 year old male. I would say my sex drive is in the high normal range. Ideally in a relationship I like to be having sex upwards of 5 times a week. In relationships in the past, I was with women who were fairly far on the other end of the spectrum...once a weekers. It was not a good situation for either of us. In addition, it takes me a long time to get off. So sex takes a while for me, an additional frustration for the women. My kink level is pretty low. I'm just excited about pretty great vanilla sex.

For a while I thought there was something wrong with me, and felt like I was really annoying the women that I was with (one in particular, who made me feel kind of bad about it). More recently, I've found that my desires and the amount of time it takes me works just fine for a lot of women. But none of those have worked out as a relationship.

So this woman wrote to me recently and she seems really cool and cute. She identifies herself as "bi". Looks sort of wholesome in a cute way. She seems funny and interesting. Basically, minus the "less desiring of sex" thing, she'd be right up my alley. Perhaps in a big way (I'm well aware that people online can be totally different in real life, but my basic guess is that she's someone I'd be interested in).

I know I'm overthinking this to some degree. But I'd hate to find myself in a situation where I like everything about someone, but this desire for sexual frequency fucks everything up, makes me feel like a jerk, makes her feel frigid and wastes a bunch of everyone's time. Given that I'm sort of given this information about her, should I just nip it in the bud? Should I explain my reservations? Should I assume that it's just a stupid dating site thing, and probably doesn't mean anything, and see what happens?

I've sort of developed the opinion that people's amount of sexual desire doesn't change much after a certain period of exploration. Am I wrong? Mine is pretty much pegged at 11, all the time.

Let he who be without sine...

phrontist — Sat, 28 Jun 2008 19:00:54 -0800

Why are sine waves considered "pure" tones? Why do we consider sinusoids the building blocks of periodic functions? When analyzing physical, electronic, and acoustic/musical phenomena, it's often handy to view things in the frequency domain. I understand the basic idea of Fourier Analysis, namely breaking apart periodic functions in to the sums of sinusoids of given frequency and phase.

What I don't get is why or how sinusoids are "special". I know in the real world a great number of objects are essentially complicated dampened spring oscillators, so sinusoids are common in nature. Is that the end of it, or is there some deeper reason this function is good at representing periodic phenomena?

Isn't it possible to do a fourier analysis that breaks an arbitrary periodic function in to the sum of any other periodic function? Why not square waves, or a sawtooth?

While sine waves sound "pure" to me, it seems highly subjective. Is there something more than convention at work here? Some property of the ear?

The wikipedia page for sine waves reads...

The human ear can recognize single sine waves because sounds with such a waveform sound "clean" or "clear" to humans; some sounds that approximate a pure sine wave are whistling, a crystal glass set to vibrate by running a wet finger around its rim, and the sound made by a tuning fork.

This seems arbitrary though.

We say that the timbre of a violin is complex because it has many different harmonics. But the very idea of harmonic content assumes some basis function, right? Could we just as easily say a sine wave is complex by choosing square waves as our basis of spectral analysis?

So is this just a convention, and if so, where do we get it?

Anyone able to find an Armenian terrestrial TV frequency list?

k8t — Thu, 27 Mar 2008 15:09:01 -0800

Armenia terrestrial television frequency list? I'm currently in Armenia and trying to get my TV tuner card to pick up the terrestrial TV stations. I have tried doing a full scan, but with no success. I know that it is a SECAM D/K set up, but I'd love to find a list of the frequencies themselves so I can input them by hand. Additionally, I am on a seriously slow dial-up connection, so my ability to surf is limited. I've already spent a lot of hours searching. Please hope me.

health effects of low frequency sound

fleetmouse — Wed, 23 Jan 2008 15:32:25 -0800

What are some reputable resources on the deleterious health effects of low frequency sound / vibration? Of course, if you think there are none and I'm a sprout eating, tinfoil-hatted addlepate, let me know about that, too... :-)

Is voltage/frequency all I need to know to bring my appliances from Brazil to the US?

AnyGuelmann — Wed, 27 Jun 2007 08:16:39 -0800

Is voltage/frequency all I need to know to use my brazilian appliances in the US? I'm moving from Brazil to NYC. I have brand new appliances down here, including a top-of-the-line dish washer I have yet to use. I'm thinking I should bring them with me... but will I be able to use them?

Provided all the electricity/instalation issues are all right, I'm thinking I can sell the stuff I don't need in the US when I get there.

The appliances I have are: fridge with separate freezer, microwave, clothes washer, dish washer. Also minor stuff like blender, iron, fan, etc.

What do I need to know? This table says both the US and Brazil use 120 V/60 HZ. Is that all? Does this mean I can use my stuff over there?

On a related note, I'm assuming rental apartments in NYC come with microwave/stove/fridge. If that is indeed the case, do you think I will be able to sell mine in the US? Should I sell them down here before I move? Also, do most US fridges have a separate freezer on top?

Walkie Talkies in Europe?

gnossos — Sat, 16 Jun 2007 10:21:50 -0800

Can I use my 462.5625 Mhz walkie talkies in Europe? I know this frequency band is for public use in the US. Is it also for public use in Europe (Netherlands, Germany and Italy)? My family of four will be in Europe for one month on vacation and want to use our walkie talkies to keep in touch with one another, instead of using cell phones.

I'm bleeding from my hands. So why can't I hear?

eritain — Sat, 12 May 2007 07:08:58 -0800

Hypotension/hypovolemia as a low-pass filter: I got cut, I went into shock, and then everything started sounding funny. I'd guess it was a 40 dB (±10) rolloff, which began near 200 Hz (±50) and left me with nothing above 1kHz. How in the world? Story, discussion of numeric estimates, off-the-cuff physiological speculations, etc... About a week ago I had a gentlemanly disagreement with a pane of glass, which left venous blood running richly from two of my knuckles. (No winner was declared, but you should see the other guy. I totally took him.) At the first-aid station, I dropped into a typical case of shock: pallor, weakness, sweating, and thirst. I knew what it was, so I got my head between my knees and asked a bystander for water to sip. I was still feeling awful when someone got a car to drive me and my now-bandaged hands to the emergency room (where those hands would get six stitches and some iodine).

As I walked some 15 or 20 feet to the car, I experienced an unfamiliar symptom: My hearing drained out. First the high end, then the mids went very quiet. A waterfall fountain became inaudible; male voices had a very flat timbre. I could hear the bass rumble of the car engine very clearly, but not its rattling-type noises, or much road hiss/tire noise.

Note that I am pretty bad at estimating loudness, but it was a profound loss. Frequency, I'm a little better with. I understood people speaking, so I must have had some hearing up to 1000 Hz (to make out the first two vowel formants). But 700 Hz is a good estimate for the top of the road hiss that I wasn't hearing, and the loudest sounds were definitely 100-160 Hz or so.

Qualitatively, here is how much shock I was in: My vision was washed out, but not tunneled. My lips, I'm told, were colorless. I did walk 20 feet, but I'm sure I couldn't have gone 40. I had the presence of mind to keep my knees slightly bent in case I went down, and to be irritated at the people who thought that holding my elbow was really gonna help if I fainted. (Arms go limp, yo?) I did not have the presence of mind to say, 'Hold me at the shoulder, not the elbow,' or better yet, 'Wait, give me a minute here, I can't walk yet.' In the car, with a few minutes' rest and some water sipped, the normal shock symptoms receded, and the hearing loss with them.

So: What was that? Has this happened to other people? Can you propose a mechanism? (Could shock drain fluid from your cochlea, or do some fibers of the auditory nerve have a better blood supply than others, or would it more likely be the auditory cortex going under?) I welcome hypotheses, but I'm not about to go gouge myself again to test them. (Hmm, guineapigs.metafilter.com is still available.)

Tools for Word Frequency Analysis

Mr. Gunn — Sun, 06 May 2007 14:52:31 -0800

Is there a recent American Word Corpus available for free? I'm playing with a little word frequency analysis just for fun, and I've found, somewhat unsurprisingly, that the British National Corpus isn't the best for comparative analysis of modern American English and it cuts off at 20 words per million. The Brown Corpus is better, but not available, the American National Corpus costs $75, and the 1st edition of the ANC is OK, and is as recent as 2003, but it would be awesome if someone knew of a corpus prepared each year, so I could look at the increase in word usage over time.

Also, I'm using the word counter from Catherine Ball at Georgetown, which is fine, but what I'm looking at doing is picking out statistically significant words, so if there was a word counter that used a corpus on the back end to produce an "expectation value" that showed the frequency of the word in submitted text in relation to the frequency of the word in a corpus, that would also rock. I could probably even make one if none exists, had I an appropriate corpus.

Finally, I'd like to hear about great ideas and tools for visualization of this kind of data.
Here's a previous related question.

Generating pure tones...

Blazecock Pileon — Tue, 17 Apr 2007 09:37:05 -0800

Generating pure sound tones at a specific power level, for recording to a CD... I'd like to generate sound with control over the following parameters:

• frequency
• channel (L or R)
• power (dB level)

1. I'd like to know if there is (free) software for Mac OS X which I can use to quickly generate tones at a specified frequency?

2. Also, is it sufficient to use an editor like Sound Studio to accurately set the level and channel of the tone?

3. When distributing a CD with these tones, are there technical issues I should know about with respect to authoring the disc, such that the power is accurately replayed on the end sound system? By this, I mean I would like to give this disc to someone, and if they played this disc, the power is accurate replayed for the listener.

What should I do to ensure this? Would I need a "calibration" track or pair of "normalization" tracks?

Can high frequency sounds transmit through windows?

SoulNoise — Fri, 30 Mar 2007 11:42:19 -0800

Can a 17kHz sound transmit through windows? I was wondering if sounds like the infamous teen buzz http://en.wikipedia.org/wiki/Teen_Buzz, which is 17 kHz, if loud enough, go through a window and thus be heard outside or in another room?

Why does my turn signal blink faster when one of them goes out?

spiderskull — Thu, 19 Oct 2006 18:30:27 -0800

Why do my turn signals blink faster if one of them goes out? This my guess is that it's because the blinking is done by a contracting and expanding bimetal contact point that makes and breaks contact periodically as it cools down and warms up, respectively (which could also be making the ticking sound). When one of the lights goes out, it's drawing half as much current, so somehow that is changing the rate at which the bimetal strip conducts heat.

That, or assuming the lights are in parallel, the resistance changes, which then changes the circuit as a whole -- maybe if there's something like a 555 timer controlling the frequency, and the resistor ratio changes it causes the frequency to double.

Can someone please verify this for me? Gruesome details would be awesome.

Excel Help for Pie Graph of Frequency of Appearance of Values in a Column?

WCityMike — Fri, 19 May 2006 11:33:20 -0800

ExcelFilter: I need help creating a pie chart as a separate worksheet in Excel that counts how often values appear in a column and creates a pie graph based on that data. I'm stumped, I'm not using the right Google terms, and my company's help desk couldn't guide me through the process, either. (That sounds awkward, so I describe it more comprehensibly inside.) I am a legal assistant whose station changes from day to day and week to week (a "floater"). I keep an assignment log as an Excel spreadsheet, detailing where I worked each day, and any personal notes about the desk.

The horizontal subject headers are "date," "secretary," "department," "practice area" (a sort of 'subdepartment'), "attorney 1", "attorney 2", "attorney 3", "attorney 4", and "notes." The vertical headers are the dates I work.

I'm seeking to figure out how I can have Excel create, and automatically update, a pie chart based on the "department" column, and, optionally, to help me break down further in some clickable way the practice area off of the respective departments. The latter is not entirely necessary if it would add too much of a complicating factor.

Let's say, for example, that the department column of this spreadsheet looks like this:

Rotor-Scooting
RealityDistortionField-Creating
GatesAssassin
Metafilter-Reading
Widget-Making
Widget-Making
Widget-Making
Widget-Making
Rotor-Scooting
GatesAssassin

I'm looking to figure out how I can get Excel to create a pie chart that would have 40% widget-making, 20% rotor-scooting, 20% GatesAssassin, 10% Metafilter-Reading, and 10% RealityDistortionField-Creating ... based on its own, updated count of the frequency of appearance of the departments as compared against the total non-blank entries in the column in question.

And if all the following week, I worked for the BallmerAssassin department, it would automatically add in the appropriate slice and udpate the chart.

Keep in mind that since the number of entries in that column will change on a daily basis, I'd prefer not to "hardcore" into any existing formula or chart or what-have-you the rows part of the range, unless it can't be done otherwise.

Is what I'm talking about possible? I thought it'd be something that Excel could do with its eyes closed, but not only did I dredge up a big fat zero when trying to figure this out, so did my business' help desk. Any ideas?

Can You Hear That Dog?

freudianslipper — Sat, 16 Jul 2005 15:41:41 -0800

How can I generate an audio frequency only dogs can hear? This link says "Dogs can hear frequencies up to about 35,000 Hz (35 kHz)".

I hope to use my computer and home monitors (BostonT830's) although i'm not sure if they are capable of broadcasting in that frequency range.

Any home methods for doing this? I have several audio apps to work in but i'm not sure how to accomplish this. Or is there a wav I can download? Thanks!

Interstitial Cystitis

pony — Mon, 11 Jul 2005 13:05:56 -0800

Does anyone have any remedies for Interstitial Cystitis? Any remedies for reducing urinary frequency? Any medications that work

My Mac Mini Display Detection Dilemma

Chunder — Sat, 28 May 2005 04:08:25 -0800

I've made the switch to a Mac Mini, and unfortunately it seems to be detecting my monitor capabilities incorrectly; how can I override this autodetection, or otherwise get around the problem? I'm using a (relatively new) Digimate L-1705 17" TFT monitor connected with the DVI-VGA adapter.
The maximum refresh rate of the monitor is 75kHz, yet when the mini boots, the grey screen appears OK - but when it changes to the normal desktop screen my monitor reports a "signal out of range" error.

I think that the mini thinks that the monitor can achieve a higher refresh rate than it really can, and is using this by default. How can I stop it doing this?

I know that the computer works, as I carted it across town to my brother - using an old 14" CRT! This enabled me to register the Apple wireless keyboard and mouse, and set up a user profile. Whilst there, I set the display preferences to a setting that I knew worked with my monitor.
Upon getting home and connecting the monitor, I got the same out of range message.

Thus far, I've been on the telephone to Apple Tech Support for over 1h, and they've been able to come up with anything more useful than their presumably standard "reset PRAM, reset PMU, boot from CD, boot into safe mode" spiel - all of which I'd already tried, and none of which worked.
Their other suggestion was to take it to an Apple store - but unfortunately this will require me to catch a 100GBP flight off the little rock on which I live. Hmph.

Carrying the mini across town is OK, if there's something that I can do when connected to another monitor - but it's not feasible to carry my monitor across town as well. I don't have any other display unit (monitor, compatible TV, etc.) on hand which can be used.

I can get into the Open Firmware (command option O F) and have had a poke around... is there anything in there (or accessible from there) which I can change to set the default screenmode? I can see the HD, but have no idea how to find/edit/remove files from the OF command line.

I can also get into the single user mode (command S) but unfortunately once I'm in there I can't do anything, as the Apple wireless keyboard is not detected. Great! I'll happily buy/borrow a USB keyboard if necessary (my PC one is - typically enough - PS/2).

There are some instructions on the Apple support site, but unfortunately this doesn't work in my situation - safe mode goes out of range, and I can't type anything in single-user command line mode!
This discussion, again on the Apple suport site, appears to be my exact problem, but I don't have the option of using a compatible CRT screen and my TFT at the same time.
I've also found a bunch of useful information on ars technica but none of it has helped with this problem. I've posted my question there, too - but have had no joy yet.

I appreciate that I've typed an awful lot so far - apologies! - but when it comes to things like this, I know that it's best to explain the minutiae of what's wrong and what has been tried... Hopefully there's someone here who knows everything there is to know about the underlying Mac architecture, workarounds, etc. - please?! (I've currently got every possible extremity crossed on the off chance that it helps...)

Many thanks in advance!

On preview: Hehe - "Extended explanation"... yup!

Portable Phone Frequencies

jacquilynne — Mon, 18 Apr 2005 10:28:33 -0800

What's the difference between the various frequency bands for portable phones? I wish to buy a portable phone / digital answering machine for my home (not a cellular phone), and have noticed they come in 900Mhz, 2.4Ghz and 5.8Ghz versions. Is there a difference between these that I should know about before buying a phone?

How often do you get xrays at the dentist's office?

fingers_of_fire — Fri, 17 Dec 2004 07:12:56 -0800

How often do you get xrays at the dentist's office? Once a year? Once every two years? [mi] After an embarrassingly long absence from attending to my chompers, I now go to the DDS 4 times a year - more than most, I believe, but he scared me into it, and I always feel better afterwards. Still, is it really necessary to pony up an additional $300 to have the chompers nuked once a year in order for him to tell me that they are alright? He's a good dentist, but he has talked me into buying various goods and services in the past that I believe had as much to do with his profits as my dental well-being. I want to be a responsible caretaker for my teeth, but I don't want to spend unnecessary money.

How does mains frequency relate to computer clock speed, or does it?

twine42 — Tue, 23 Nov 2004 06:57:12 -0800

Electricity and computers. 3 questions about:
1] Mains frequency
2] Computer clock speed
3] Putting 1 and 2 together. [~240v inside] 1] At school we were told that the mains supply isn't a constant 60Hz, but that the average over a day was 60Hz. The theory was that under heavy load during the day, the power system runs slow (lets say 58Hz) and that during the night the system crept up to 64Hz to compensate. Was this ever true, and is it still so?

2] How do computers regulate clock speed? Is it analagous to a quartz chip in a watch, or does it multiply the frequency supplied at mains?

3] Does this mean a PC (theoretically) runs faster at night?