again.. the voice is not predictable.. i have seen one application to hum
out a backgnd noise.. where our man sends a 180 deg out of phase wave.. but
it was predictable.. lotsa neural netwrk fundas would help in prediction..
Alok



> -----Original Message-----
> From: Plunkett, Dennis [SMTP:dplunkett@AIRINTER.COM.AU]
> Sent: Wednesday, April 12, 2000 4:11 AM
> To:   PICLIST@MITVMA.MIT.EDU
> Subject:      Re: [OT] INVERTE THE WAVE
>
> > -----Original Message-----
> > From: WF [SMTP:wf@BLUSOFT.ORG.BR]
> > Sent: Wednesday, 12 April 2000 1:50
> > To:   PICLIST@MITVMA.MIT.EDU
> > Subject:      [OT] INVERTE THE WAVE
> >
> >     Hi,
> >
> >     A student is studyng how to invert some wave...
> >
> >     He intends to NULL some produced sound...in the factory that he
> works
> > have some TEXTIL machines and intends to reduce the noise produced by
> > them...applyng a inverted wave...
> >
> >     Does someone have some suggestions about this? Formula, site, etc...
> >
> >     I think that is too hard!
> >
> >     Miguel Wisintainer
> >
> >
>         To this I agree, as your student will need either the impulse
> response or the fourier transform of the environment in which the machine
> resides. All this is DSP type stuff, and will require several (Lots) of
> measurements, as it is not just a simple task of invert the wave to
> cancell
> it out, he will also have to remove harmonics and the like etc. Too much
> stuff to go into for this list.
>
>         Dennis
> >