Jim Frohoff wrote:

>>That wouldn't work, since white noise is random. Hmm, or would your brain
>>just learn to ignore that frequency band? If it does, then why can it not
>>ignore the tinnitus? My undrstanding of the ear and related systems falls
>>down here :-)
>
>
> Thanks for the reply -
>
> Here's a ref to TRT treatment for tinnitus that utilizes the white noise
> masking : http://www.epleyclinic.com/trt.htm
>
> I have located several references to generating white or pink noise with
> DSP, so it looks do-able, though this will obviously be a huge amount of
> learning ahead for me. My guess is that I just create the white noise and
> then setup my two or three bandpass filters to let through what I need to
> mask the tinnitus frequencies.
>
> Any suggestions to DSP kits / software that come with some of the code
> libraries I will need to start learning how to do the compression, limiting,
> eq and white noise generation? I have just spent the afternoon hours
> reading everything I can find on the TI dspvillage.com site.
>
> Jim
>
>
>
>
>
There are a lot of ways to do this. Analog Devices makes an analog
volume compressor that has nice features. It can be made to output a
maximum level without much distortion. A very fast attack time can
simulate a clipper without generating harmonics the way a clipper does.
The gain for low levels can be limited, so ambient noise isn't amplified
to a distracting level. The noise generators can be analog too, and
summed in, at a point to keep them unaffected by the input level, ot to
rise and fall with it. You can do all of that with the DSP too, but it
may not be as easy for you to tweak: you decide. Start with one channel,
then go DSP stereo once you know what's wanted. It's possible to twist a
pot while you keep listening. With a reasonable program, you have to
recompile or at least load a new table to do the same thing, and A-B
comparison becomes hard.

Jerry
--
"I view the progress of science as ... the slow erosion of the
tendency to dichotomize." Barbara Smuts, U. Mich.
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