sampling sound, how to capture the information of different "tones" ?

Started by Nimo in comp.dsp10 years ago 6 replies

Hi.., well, in frequency domain if we sample a "sound" signal, actually we are sampling "amplitude values" at discrete places of the...

Hi.., well, in frequency domain if we sample a "sound" signal, actually we are sampling "amplitude values" at discrete places of the wave. what my point is.., if we sample this simple sound wave shouted by 2 persons => " ‘cogito ergo sum’ – I think therefore I am " the sentences is same, but their "tones" are different how that information( tone difference ) is captur


Produce Audio Sound via Inverse FFT on Spectral Data

Started by louis in comp.dsp14 years ago 10 replies

Hello, I am using C++ on a linux little endian machine, and am interfacing to OpenSound system to produce my audio sound. So my goal is to be...

Hello, I am using C++ on a linux little endian machine, and am interfacing to OpenSound system to produce my audio sound. So my goal is to be able to reprduce the correct raw sound data corresponding to spectral data I already have (for example, I know the frequency versus power information for at least 128 bins, and over about 30 time points per second) I am using the four1 function found...


Microphones position for sound source localization

Started by lapidarylee in comp.dsp10 years ago 3 replies

Hello, I've recently studied some papers about sound source localization method. As I know, 3D sound source localization can be done by Time...

Hello, I've recently studied some papers about sound source localization method. As I know, 3D sound source localization can be done by Time Difference of Arrivals (TDOA) & Generalized Cross Correlation (GCC) methods with four microphones placed on different plane. Its a question about microphone position, how can I place them well for optimization ?! If the environment is a public squar...


what does an analog TV demodulator really do?

Started by dtsao in comp.dsp11 years ago 10 replies

Hi, I am confused about the exact function of an analog TV demodulator. Does a demodulator for an analog channel take as its inputs already...

Hi, I am confused about the exact function of an analog TV demodulator. Does a demodulator for an analog channel take as its inputs already separated CVBS and Sound IF signals, or does it take as its Input the the full analog channel (including video and sound) at baseband (or IF?) and then filter/separate the CVBS and Sound IF as it's Outputs? Take for example the following process: 1) Take ...


Any link for downloading sound files easier to localize

Started by riz in comp.dsp12 years ago

Is there any link for downloading sound files that are easier to localize in real time environment?for example,sound files involving impulses...

Is there any link for downloading sound files that are easier to localize in real time environment?for example,sound files involving impulses etc? Thnaks _____________________________________ Do you know a company who employs DSP engineers? Is it already listed at http://dsprelated.com/employers.php ?


Symbol Synchronization for QPSK

Started by Praveen in comp.dsp13 years ago 4 replies

Hello all, I am trying to fix up my symbol synchronizer for QPSK using early-late gate method. Now the whole idea is this: I generate a...

Hello all, I am trying to fix up my symbol synchronizer for QPSK using early-late gate method. Now the whole idea is this: I generate a qpsk wave and save it as a sound file in one system. I play the sound file and the sound file gets recorded through a mike in another system about 2m away. Now, the problem with the received file is that there is no constant envelope (which is obvious...


DTMF decoder

Started by jals6984 in comp.dsp13 years ago

hello, I need to make a dtmf decoder using java. And it has to be decoded using the pc sound card. Right now all i can do is connect 2...

hello, I need to make a dtmf decoder using java. And it has to be decoded using the pc sound card. Right now all i can do is connect 2 phones through my modem. Any suggestions on how do i map the modem sound onto my pc sound card? My modem does not have a connection for a jumper. So i need to know how can i do it without a jumper. Secondly.. Which algorihtm is preferable? U...


Position estimation to sound source

Started by analyser in comp.dsp13 years ago 5 replies

Hi, I am doing this final year project in estimating the position of sound source. I have constructed two detection sets with each of...

Hi, I am doing this final year project in estimating the position of sound source. I have constructed two detection sets with each of four microphones. Each of these detection sets will yield a direction. Knowing that distance apart, we can localize the sound position in space. The problem now is I have to consider the direction of each detection set first. How do I calculate out the azimuth a...


How to measure quality of reconstructed sound

Started by peter1 in comp.dsp10 years ago 2 replies

Hi all, I'm working on a project that requires to reconstruct the input sound and evaluate the quality of the output. I have different...

Hi all, I'm working on a project that requires to reconstruct the input sound and evaluate the quality of the output. I have different kinds of sound (speech, vehicles, birds, ...) in both digital and analog. I was able to reconstruct them. I thought about SNR to measure the quality of the output but I don't know how to measure SNR. I'd appreciate if you can tell me either how to measur...


Sound Card Question

Started by Shytot in comp.dsp14 years ago 1 reply

How does a sound card set its anti-aliasing filters? After all, you can program a sound card to read at say 44.1kHz or 22,050Hz or half of...

How does a sound card set its anti-aliasing filters? After all, you can program a sound card to read at say 44.1kHz or 22,050Hz or half of that again so how do the ani-aliasing filters change? Switched cap filters are sampled filters so they would not be good and digital filters are no good either as we need analogue filters jus before sampling. Shytot


Anybody know about sound propagation in water? (sonar)

Started by Anonymous in comp.dsp5 years ago 5 replies

If you were to drop a liquid contaminant into the water, would the sound refract due to the difference in speed in the new medium?

If you were to drop a liquid contaminant into the water, would the sound refract due to the difference in speed in the new medium?


binaural 3d sound localization in reverberant room

Started by riz in comp.dsp12 years ago 5 replies

Which algorithm is most effective in binaural 3d sound localization in a reverberant environment(using only two microphones)?.i have tried...

Which algorithm is most effective in binaural 3d sound localization in a reverberant environment(using only two microphones)?.i have tried to localize sound in 3d (reverberant environment) using hrtfs i.e convolving the left and right microphones inputs (each of 512 samples) with 710 available inverse hrtfs and then correlating them.it doesnot give good results especially the elevation estimation ...


basic question about HRTF based sound localization

Started by Sylvia in comp.dsp12 years ago 3 replies

I have basic question about the HRTF based sound localization.Do the HRTF based sound localization algorithms suffer from front-back...

I have basic question about the HRTF based sound localization.Do the HRTF based sound localization algorithms suffer from front-back ambiguity problem?I am trying to use one of the HRTF algorithms to detect sound source direction in azimuth in the presence of noise,sometimes,it detects the azimuth symmetrically in the back plane when source is infact in front planeand viceversa.What can be the r...


phase addition to spectrum of signals and reconstruction

Started by adj in comp.dsp14 years ago 7 replies

i have a question regarding phase randomisation and its effect on the signal. i took the fft of a sound file. to its phase part i added a random...

i have a question regarding phase randomisation and its effect on the signal. i took the fft of a sound file. to its phase part i added a random phase. and from the magnitude part i subtracted the magnitude of the spectrum of noise which in magnitude was very less compared to the original sound (simple spectral subtraction). i then reconstructed the sound file thus edited by taking ifft. all ...


Generating sound from an image file

Started by Anonymous in comp.dsp12 years ago 2 replies

Hi, How do I generate, using free tools, a series of concentric spheres on the time-frequency axis and produce a sound file from...

Hi, How do I generate, using free tools, a series of concentric spheres on the time-frequency axis and produce a sound file from that? Michael S.


Simple audio experiment

Started by salaria in comp.dsp12 years ago 4 replies

Hello, I just did a simple audio experiment and it failed... if you could comment on it and/or suggest some changes to make it work: i have...

Hello, I just did a simple audio experiment and it failed... if you could comment on it and/or suggest some changes to make it work: i have a walkman which is in very good condition. the output sound quality of hte walkman is excellent. i connected the output of the walkman to the computer mic socket using a simple audio sterio cord and recorded the sound using sound forge in a .wav file. N...


Sound Capturing

Started by kiplring in comp.dsp16 years ago 1 reply

Is there anyway to capturing the speaker-out-sound( not from microphone)? Any Library, or Win-API welcomed. Thanks.

Is there anyway to capturing the speaker-out-sound( not from microphone)? Any Library, or Win-API welcomed. Thanks.


Gadget tip: Sound recorders

Started by Rune Allnor in comp.dsp10 years ago 6 replies

Hi folks. Today I went by the local gadget shop and found some sound...

Hi folks. Today I went by the local gadget shop and found some sound recorders: http://www.samsontech.com/products/productpage.cfm?prodID=1901 http://www.rolandus.com/products/productdetails.aspx?objectid=757 These things are small (about 12 cm x 8 cm x 2 cm) and basically contain a couple of microphones, a sound card and a memory card for storage. They record data either directly to ...


Clipped before FFT

Started by Robert Scott in comp.dsp6 years ago 28 replies

I have been experimenting with some time-domain pre-processing to improve the reliability of an FFT application. The application is extracting...

I have been experimenting with some time-domain pre-processing to improve the reliability of an FFT application. The application is extracting the RPM of an engine from the sound it makes. Prior to these experiements I was using straight FFT of blocks of time-series sound data. An engine generally makes a sound rich in harmonics, so the FFT should have evenly spaced peaks. When the peaks ...


how does one change the timbre of a sound

Started by jeanbaptiste36 in comp.dsp14 years ago 6 replies

I was wondering how one changes the timbre of a sound without changing the pitch. Igor

I was wondering how one changes the timbre of a sound without changing the pitch. Igor