sound amplification help

Hi.I need to record some enviromental sounds (not speech).I tried my pc's microphone but it cannot even record sounds i can hear without any device.I want to hear barely noticable sounds loudly.Sound quality and distortion is not that important.Mic wil be used indoors and sounds will be recorded to pc.C an you offer me any simple solutions.I dont know much about electronics.I can make a pcb if you send schematics or simple things like that.Thanks

You neede a microphone amplifier with more voltage gain.

There is a small speaker icon at the right bottom corner of your computer screen. double click on that icon. volume control will be opened. go to options->properties and from below the show the following control options scroll down to select Microphone and click ok. Microphone control will be shown in your volume control. increase its volume now it would be able to catch sounds form larger distance.

Sorry for replying lately

I want to record footsteps or more accurately people on the stairs of my apartment.An audio detection software (like Sound Detection and microphone monitoring software - Zone Trigger) will email me recordings whenever it detects someone so that i will know if someone is waiting for me inside the building.It may sound paranoid but there were some incidents around here lately.

I bought a cheap USB microphone and increased its volume from microphone control as you suggested and made some recording with audacity software

audacity software (to open the recording):

Audacity: Free Audio Editor and Recorder

recording:

2shared - download 1.aup

Recording is amplified with 35db gain.I cant use audacity for my purpose because it doesnt amplify sound realtime.

My flat is on the second floor.In the recording i descended to the ground floor (at about 38th second) and then began climbing.

I want to be able to hear footsteps two floors up and down.Is there any cheap and simple solution for a much more louder and clearer recording?

specifications of the microphone i used for recording:

omni-direction
output impedance:1.4k+-30%

frequency response:50~16khz

sensitivity:-58db+-2db

operating voltage:1v~10v

current consuption:0.8ma max

s/n ratio 40db or more

I have Audacity but I don't know how to use it to play your file that I downloaded.
I think footsteps two floors away will be too faint to be used by the software that e-mails you a warning. Also it might produce many false alarms from background sounds.

The recording sensitivity depends on your sound card. Some better quality sound cards have Mic Boosting facility. Recording is not a problem but the sensitivity needed to pick the foot steps sound is the problem. You need an over sensitive mic or sound picking up circuit. May you need to assemble an external small mic amplifier and connect it to the Line Input of your PC if it is over amplifying in mic jack or you can integrate a level control for the required amplification.

Audioguru said:

I have Audacity but I don't know how to use it to play your file that I downloaded.

Click to expand...

Importing doesnt work.I right clicked chose properties chose open with audacity then double clicked.

When I use Audacity to open the sound file then I get this error:

Hi Audioguru,
Which Windows you are using? Download Beta version 1.3.13 of Audacity, gives no problem with any windows. Error you specified says corrupted installation. I am using Audacity for the last 1.5 years without any problem. Earlier I was using Audiomagic 2.11 but it does not work with Windows Vista or Seven so I had to switch over to Audacity. I was using version 1.2.6 and even that did not give me any problem. But above all these I prefer to use Cooledit 2000 (the complete Audio Studio). Hoping to get you on Audacity road without problem. :smile:

Raza said:

Hi Audioguru,
Which Windows you are using? Download Beta version 1.3.13 of Audacity, gives no problem with any windows.

Click to expand...

I have windows XP Home.
Today I downloaded Audacity 1.3.13 Beta but the old version (1.2.6) was selected when I clicked your 1.aup file. I could not change the "open with" to the new Audacity so I deleted the old version. Now I cannot make your file "open with" the new version, instead it opens with Internet Explorer which is wrong.

Manually opening the new version and importing the "raw data" of your 1.aup file gives a moment of some kind of sound which is wrong.

---------- Post added at 15:26 ---------- Previous post was at 15:00 ----------

I deleted Audacity Beta program and re-installed it. Then clicking on your 1.aup file got Audacity Beta to open with the same error as before with the old version.
So I deleted your 1.aup file and re-downloaded it and the same problem occurs.

With my utmost effort I could not download your file. It says click on 1.aup to download, clicking results to come back to same page without download.

hexe
When you save file as "aup", Audacity saves the sound data also in a directory named after the original recording file name in the same directory where you save the original recording project, the data directory is named as (file name)_data. If you want to open any .aup file on some other computer you have to save that data directory on that machine in the same directory where you save the .aup file, otherwise the file will not play, as audioguru is facing the problem. It is not his program problem but that Sound Data problem. Why do not you export your file, so any program can play that file. Better export as .wav file.

I exported the file as wav.I couldnt upload the file since i have problems with my connections right now.I will upload the file as soon as i can.

I set my Windows Media Player to show a 'scope on the monitor. Your recording has so much background noise (electronic noise) that the distant footsteps could not be seen but they were heard. A detection circuit will not see them.

There are clear low frequency peaks that show in a spectral representation. I think, they are easily detectable in the present case. It becomes a more difficult problem, if you consider other possibly concurrent sounds.

I listened again. There was the sound of an elephant or somebody stamping their feet in the stairway.
A mugger wouldn't make so much noise.
The earthquake sounded interesting. Also I am surprised to hear a loud air conditioner running (or a jet airplane flying) in the stairway.
Good luck trying to detect a mugger.

Suggestion: move away from this ghetto. The people in my neighbourhood are friendly and civilized.

The people in my neighbourhood are friendly and civilized.

Click to expand...

:lol:

Yes the foot step sound seems to be the back ground Music for the main Noise.
If you are still after this project, you have to pick up the approximate frequency of the foot steps sound and use Audio filters to segregate and amplify that spectrum.