Re: Do you recognize this sound?

On 5 May 2005 01:35:27 -0700, "Herbert Blenner" <a1eah71@xxxxxxx>
wrote:


>
>If your sonar is an accurate representation of the 900 Hz component
>then I would appreciate further details on how you extracted it from
>the other signals.
>
>Herbert
>

If you want to extract the signal yourself using your FFT, then it is
quite simple. Run the FFT. Set all the values up to the 800Hz point to
zero. Do the same for points from 1kHz upwards. Now run the IFFT and
you have a filtered version of the original, with just the 900Hz
signal and a bit of noise - similar to what I posted, but without the
extra joke effects.

d
Pearce Consulting
http://www.pearce.uk.com
.

Relevant Pages

  • Re: Analyzing fundamental frequencies from musical signals
    ... This is about analyzing fine detail in pitch and pitch changes ... As you found, zero-padding and using a long fft, although a very ... Plot that phase difference. ... accurate and reliable on real audio signals. ...
    (comp.dsp)
  • Re: Secure passwords?
    ... >> noise using FFT integration. ... An FFT is an FFT is an FFT is an FFT! ... As an index of how commonplace an EE problem extracting signals from ... metallic-deposition-layer glass used for emsec shielding where visibility ...
    (alt.computer.security)
  • Re: Oversampling and the FFT
    ... I suggested we sample just above Nyquist and perform our 1024 point FFT. ... regardless of the window function or sample rate. ... Also the phase of a sharp filter may change ... signals near the Nyquist frequency of a given sampling rate than ...
    (comp.dsp)
  • Re: Discrete Deconvolution
    ... I'm analyzing some time signals for periodicities, ... a window function, and s is the actual source signal. ... I know the FFT ... The FFT can be used as an approximation of the Fourier transform of a signal in sampled time with an infinite number of points, which is in turn an approximation of a signal in continuous time that extends into infinity. ...
    (comp.dsp)
  • Re: [LTSPICE] crystal circuit modeling settling time and certainty
    ... >>> is there a way to specify nodes to always be used in the FFT? ... > from that trace it never seems to remember wich signals i used before, ... Then save this plot settings to a file for later use. ... selected in the first selection box. ...
    (sci.electronics.cad)
Loading