Filtering noise over 200kHz

Hello!
I'm recording rat ultrasonic vocalizations at 1MS/s using a PCI-6132 DAQ. A colleague of mine is analyzing the sonographic data from the recordings, and asked me to apply a filter to the signal as it's recorded. The specifications he asked for was to "filter noise over 200kHs, with a reasonably steep slope". I have no background in auditory analysis, so I have no idea what he's talking about, or how to impliment it. Can anyone interpret this and help me figure this out? Thanks!
Matt
Solved!
Go to Solution.

When I have been required to filter signals in LabVIEW, I have had success with the express VI called "Filter". You can find this in the following Palette: "Signal Processing -> Waveform Conditioning -> Filter.VI.
Before we get started, I noticed your requirement is to filter "noise over 200kHz". Does this mean filter everything over 200kHz or just "noise"?
If you are to filter everything over 200kHz, there are several parameters you will need to set to accomplish your goal. Double click on the Filter.VI once you have dropped it on the block diagram. The first thing you need to set is the fitler type. If you want to filter everything above 200kHz and pass everything below 200kHz, you want a lowpass filter.
Since this is a low pass filter, you will only have one cutoff frequency. This is 200kHz is your case, since you want to pass everything below 200kHz.
To get a steep slope, I like to use the elliptic topology. You can start with an order of 3 to see if this produces the response you need.
I'd recommend researching filters on a site like Wikipedia if this doesn't produce the outcome you need. Using this VI will get you where you need to go, but you may have to adjust the parameters based on your signal. However, I think this will at least get you started in the right direction!

Similar Messages

Superdrive Making Noise Over Music

The Superdrive on my Dual 2.3 G5 has started making odd interference noise over any music that is being played from a disk. The noise is then imported into iTunes over the track. At first i thought it was an iTunes problem but it does it when audio is imported into my audio software (Digital Performer) from a disk. I've cleaned the drive using a lens cleaner, still does it. I also thought it was doing it on just CDR's but it now does it on commercial CD's too. Is it time for a new drive ?

Hi cxi2001-
That is certainly an odd problem, but I would imagine that there is something within the drive that can fail that would cause such problems.
The good thing is that if you are handy you can pick up a new drive for around $35US and install it yourself.
Luck-
-DaddyPaycheck

Loud BEEEEEEEEEEEP noise over Music

My IPOD is making a horrible beep continous beep noise over the music. Any help is appreciated.
BoxingCritic

If the files are .mp3 files...they won't work for some reason. The ipod is supposed to be able to play .acc, .wav, .mp3, and a couple other files that i can't think of off the top of my head, but for some reason the mp3 doesn't work. I was having this same problem but then converted all of my .mp3 songs to .wav and they work fine now.

Hard drive and mouse noise over speakers

Hello all,
I have a iMac and just recently have noticed hard drive, mouse and buzzing noise coming over my powered speakers. I have been a home recoding musican for the last 10 years and just recently moved to California. Since I've been here I'm now hearing all of this unwanted hard drive, mouse and various other noises coming thru my powered speakers. Even turning down my speakers to 0, having a deadicated power strip/noise surpessor on ALL of my devices, im still getting these noises. Like moving the mouse you hear staic thru the speakers.
Any idea where to start looking into this problem? Need a solution as this is killing me.
thanks for your help in advance.
- M

I hope this helps...
I also had a problem with fan noise. It not only creates more than normal noise, but i notices a difference in my battery life... it was really bad.
Well after using istat pro i notices a activity that took up about 85%-95% of my processes.... And stated 'Canon ip5000'.... this was my printer that wasn't attached!
I opened activity monitor to search for this process... i couldn't find it under that name. However, i did notice a printer agent of sorts (i can't remember what it was called).
Anyway, after quitting this process my fan almost immediately went from 6000rpm to 2000rpms and the noise was almost gone! And my battery life that was sitting on 24 mins (after a full charge and 40 mins!!) and then went up to 1hr15mins!
What a difference.
I'm using tiger... and the only difference that remember doing was updating the printer driver... hey presto.
I'm sure that is the issue with a lot of people... that some sort of deamon is running in the back ground and is taking an alwful lot of processor time!!!
Hope this helps!

My AppleTV 3 makes a horrid noise over the speakers when I play movies in Netflix.

This problem just started and it seems to be only on certain videos. For example: all of the episodes in Season 1 of Dexter work just fine, but as soon as you try to play season 2, it makes this horrible rattling noise like a rattle snake and no other audio comes out. Has anyone else had this problem? I tried unplugging it and plugging it back in, but to no effect.

Have you tried adjusting the "Audio Out" and the "Dolby Digital" settings in settings > audio and video? It may be worth trying several combinations of these settings, although typically it is the "Dolby Digital" setting that causes most problems for users.

My computer is playing a "drum" noise over and over

There is a constant noise playing on my computer on loop. It sounds like a synth drum. Reading other posts I found people say it might be the keyboard error sound on repeat. I opened the onscreen viewer for my keyboard and tried to see if it thought a key was being pressed. nothing. I turned off the option to play user interface sound effects. Nothing. I have closed and opened the computer. I have restarted. Nothing. The sound goes away when I mute my sound but otherwise is persistent.

It didn't fix it but it lead me to figure out what the issue was. Thanks for that! It was a webpage that for whatever reason was causing my computer to make this noise even after restarting and a full shut down. I just closed the page and opened it in a new tab. No issue now.

How do I get rid of the white noise that plays over my music?

Hey.
I got 5 CDs today and I wanted to upload them onto my iTunes to put on my iPod. But when I put in 4 of the CDs I got white noise over the top of the music making it unlistenable. But the 5th album(Double CD) worked perfectly fine. I know the problem isn't the CDs because I played them through my PS3 and they were absolutly fine. If anyone can help. Its greatly appreciated.
Thank you.
- DowellG8

Go to Edit > Preferences > General > Import Settings and check the box for error correction, and then try one of the problem CDs again.

MSI Z68a GD65 G3 Buzzing noise of hard drive over speakers

I finished building system
MSI Z68a GD65 G3
Fractal design define r3 case
Core i7 2600k
2x MSI N460GTX 1Gd5 OC
16 gb DDR3 Ram
Corsair HX 850w PSU
CORSAIR GT3 90 gb ssd
Logitech Z5300 speaker set 5.1
+bunch of samsung 1 tb spinpoints
I noticed when i scrolled with my mouse wheel up or down, i hear a interfering noise low buzzing noise over the speakers 5.1 which are conected to on board sound card.
When i connect my headphone the sound still exists
It also occurs when i start up some applications and the hard drive is busy.
I tried enable/disable eup2013 and c1 and intel c1 etc... nothing works
With or without overclock it doesn matter.
Does anybody have a suggestion how to fix this problem? Thank you! Please help;-)

Sounds like a bad earth somewhere.
Is that a wired mouse ? Have you tried another mouse and keyboard ?
Can you test the board outside the case, on a non-conducting surface. No device used for the test to be mounted in the case.

How can I copy filters between accounts?

I seem to remember, back when I first switched my email to Thunderbird about two years ago, that I could duplicate message filters between email accounts rather than recreating them manually. Now I cannot find any way to do this. I'm reinstalling everything on my system, and while I copied my Thunderbird folder in its entirety from my backup, the filters carried over on only my primary account; my other accounts have no filters attached to them.
I have nine different email accounts set up in Thunderbird (and no, I cannot consolidate them or forward some of them into another, as these need to remain separate for a variety of reasons), and about half of my filters should run on all nine accounts (they apply color-coded tags based on source and keywords). I tried a filter import-export extension, but it wouldn't import anything. And I really don't want to manually recreate two dozen filters across nine accounts, one filter at a time.
If I can't copy or duplicate the filters from within Thunderbird, is it possible to go into the file system and copy individual files within the Thunderbird folder to accomplish the same result? I haven't identified anything in that folder that would allow this, but that doesn't mean it's not there—only that I don't know how filters are stored.
Suggestion for a future revision: Change filter management so that multiple accounts can use the same filter without having to duplicate anything. You can have a master filter list where you set up the actual filters, and each email account has a window where you choose which filters that account uses and what order they run in for that account. I can envision exactly how it should look and work, but I don't have the programming skills to write it myself, either as an extension or for inclusion into the main codebase. (I'm not even sure the way I would want this to work can be done as an extension, as it seems to me it would require a deep under-the-hood change in how filters and accounts are matched.) I'd be happy to provide interface mock-ups and detailed descriptions of the desired functionality, if there's someone interested in doing the actual coding.

Yes you can,
The filter-files are in your "profile"\mail\"account"\
and in "profile"\imapmail\"account"\ and are named msgFilterRules.dat
You can open it in a texteditor (Notetab) and edit or you can copy from one account to next. Be a bit careful so you dont use filters where you dont want to.

Noise on PCMCIA DAQ 6024

Why does PCMCIA 6024 DAQ card generate noise over signal where PCI 6034E does not ? Where is the problem ? Using the same LV version 6.1 on both machine (Pc) and same OS (Win2000)

Hello,
Some portable devices do not achieve the same accuracy levels of PCI DAQ boards. For instance, noise that did not occur on the PCI version sometimes appears in measurements taken with a portable DAQ device. This noise results primarily from the size difference.
In the links below you can found some link that explain how to resolve this problem :
http://digital.ni.com/public.nsf/websearch/3C6360322410D7A786256E1D0070C375?OpenDocument
http://digital.ni.com/public.nsf/websearch/4B929520C216A84986256BEA00452C77?OpenDocument
Hope this helps.
Sanaa T
National Instruments

Noise coming out of Airport Speakers once Airfoil installed

Hiya,
I installed Airfoil and Reemote Server today in order to make all the audio work with my Aiport speakers.
It worked fine through Safari for about 10 mins and then I started getting this white noise sound coming out of the speakers.
I am trying to figure out why.
It stills plays whatever it is (mixcloud, youtube ) but one the top of the noise.
It works fine from my Iphone Itunes but the problem is from my Mac.
Any help?
Thanks

On the Airfoil for Mac site, it says that the demo will work fine for 10 minutes and then it will generate noise over the music. The license for the software is $25.

Color Correction + DVD/MPEG Compression Produced Noise

I recently color corrected a 3-hour rock concert using FCP and a broadcast monitor. When played from the timeline the concert looks great however after outputting, MPEG compression and authoring a DVD there's video noise over the image. Almost snow like but different. I'd post a screengrab but I can't seem to take one in DVD Player. Any advice?

That's exactly right Jonathan, you need to add the 2:3 pulldown, and I can tell you all why. (I read the post from Max Average, but I'm not commenting that separately)
The DVD specification simply does not support video marked as 23.98 fps (which is how Apple wants to call it) or even 23.976 fps (which is what MPEG-2 calls it). This means that for NTSC DVDs you can only use MPEG-2 video files which are marked as 29.97 fps. This is true whether your encoder (like Compressor) is letting you be aware of it or not. There is no "native 23.98 frame rate" on a DVD and the right way of making the decoder believe it is 29.97 instead, is to use 2:3 pulldown. Any other method would just be wasting bandwidth/bitrate or picture quality, depending on which way you want to look at it.
The 2:3 pulldown process, as specified by MPEG-2, is a way for the encoder of describing to the decoder which of its already decoded fields it should be repeating (displaying once more) and when. These field repetitions are designed to increase the interlaced displayed frame rate from 23.976 to 29.97. This "new" frame rate must be explicitely written into the .m2v stream, to be accepted by a DVD authoring tool, e.g., DVD SP.
I am sure many of you may wonder why it is called "pulldown" when in fact the frame rate seems to be going "up" from 24 to 30, as I did myself back in the nineties;-)
The way to wrap ones head around that, is to think about what whould happen if you just mapped 24 FPS film frames onto the NTSC TV standard which has to display frames at nearly 30 fps on a TV. Of course the movie would run 25% FASTER on a TV than it did at the cinema/picture theatre. In that perspective, the solution had to be to SLOW DOWN (pulldown) the presentation speed on a TV. The engineers of that time (this was long before color TV was even invented)
were faced with a need for film (Hollywood movies) to be translated for TV broadcasts). Of course they could not change the 30 fps used for TV broadcasts (29.97 fps came much later when colors were added;-), so they had to come up with a scheme which made each film frame seem to last 25% longer on the TV screen, than it would have otherwise. "Pulling down" the display frequency from, the physical 30 fps to match the experienced 24 fps was accomplished by letting every other frame be displayed for 50% longer on the TV. On average that is of course 25% longer (slower) which was the goal.
I may be monitoring this thread for further comments.
BTW, BitVice 1.7 runs surprisingly well under Rosetta.
Roger Andersson / Innobits AB, Makers of BitVice MPEG-2 Encoder for Mac
http://www.innobits.com/
As per Apple Discussions Terms of Service:
"I may receive some form of compensation, financial or otherwise, from my recommendation or link."

Noise on line and long disconnects since repair

Hi there. I posted on here previously. Had a major line fault just after activation. Basically something blew and the line died as soon as I tried to use bb but a line check showed as ok. Based on advice on here, arranged for an open reach engineer to visit. He identified a fault with the cabinet outside and tried his best to fix it.
During and since
-The engineers box failed to do some of tasks he asked of it while he was testing the repaired line. The guy even phoned in about it.
-He said there was brief noise on the line but his box was acting up and I was to keep an eye on it.
-The broad band keeps disconnecting for long periods and massively dropping sync when it does comes back. (syncs at 19.25 Meg then drops to 9.30 Meg). I normally have to reboot the hub to regain full sync from there.
-The phone line, when receiving a call, causes the bb to drop the connection.
-The phone line keeps getting interference, I believe from the bb line. Can actually hear computer noise over the line, not just crackling.
Think the lines still faulty and even crossed to a degree. Just swapped out the micro filter for a second time to test all the same. Do you think I maybe need to get open reach out again?
Solved!
Go to Solution.

from your description I would get engineer again
If you like a post, or want to say thanks for a helpful answer, please click on the Ratings star on the left-hand side of the post.
If someone answers your question correctly please let other members know by clicking on ’Mark as Accepted Solution’.

Anyone ever hear a loud high pitch noise

For the past week, I have heard a high pitched noise from my imac. It usually occurs when viewing videos and will go away once computer is shut off. It does ring when booting back up then goes away until a video or song is being played on the computer. Apple Support told me it wasn't something they could fix because the noise was heard during reboot. Any ideas? Thanks

Please describe "loud"... I hear once in a while a clicking noise that I know is coming from the hard drive while there is a lot of activity. It is noticeable, but I wouldn't say it's loud. My MacBook Pro does the same thing and at some point I was concerned but I found out that these noises are "normal" during a lot of disk activity.
I would still call or bring it to an Apple service store like the above suggestion, just in case! If you don't live near a store, maybe they will be willing to hear the noise over the phone? Just a thought.
Manolo.

RAW nikon files have huge Chroma Noise in Lightroom

How come when you process Nikon D3 NEF files in Lightroom it brings out Chroma noise and almost covers up all the luminance noise when importing the file without applying any preset?
When I open the same file in Adobe photoshop CS3 or in Capture NX2, the file contains almost no Chroma noise, but is dominated with luminance noise. I prefer luminance noise over chroma noise since it is forgivable on prints.
Luminance noise is that grainy tiny colorless black dots, and Chroma noise is that large rainbow color big dots. They are especially visible in grayish or dark areas.
Anyone know why this is happening to me in Lightroom 2?
Thanks

"Lee Jay - 10:42am Aug 15, 08 PST (#21 of 26)
but when I try that image in noiseninja I get a result close to the capture result - far better than Lightroom.
Does NoiseNinja process raw images?"
Apparently Lee it does. I have pasted below a reply from Bibble to a similar discussion in another forum. So technically it is possible, but LR and Aperture choose not to implement raw plugins at this time.
"There are many things that are better done in the full raw image processing pipeline that can't be done as well after the conversion....Noise being just one example. It has nothing to do with being a tiff or not, thats just another inconvenience.
All the plugins that I just pointed you too work within the confines of the raw pipeline. They don't require additional steps, the don't need intermediate files, they are non destructive, and generally they will give better results then plugins or external editors run after the conversion.
For the moment, AFAIK, Bibble is the only program that allows such plugins, and they offer great quality , flexibility and workflow.
Eric"

Filtering noise over 200kHz

Similar Messages

Maybe you are looking for