Pushing the Envelope™
with Fine Structure Processing
For a simplified explanation of fine
structure, we can use the painting "Sunday in The
Park" (by Georges Seurat) as an example.
If we look at the “envelope” of the painting, we see the elements of the scene: a lake, people
sitting and standing, trees, dogs, etc.
By selecting “fine structure”,
we zoom in on a small section of the painting, which appears
to be made up of random dots. In fact, the whole painting consists
of these small dots – but they are only visible when we
look at the painting very closely.
Finally, when we select “Envelope
and Fine Structure”, we see the result of combining
the envelope and the fine structure. The details provided by
the fine structure give the whole painting more dimension, texture
and shading.
Similarly, in acoustics, fine structure is what gives sound
detail, depth and dimension. The envelope provides enough information
for speech understanding, much like a paint-by-number drawing
gives us a good sense of an overall picture. But the details
contained in the fine structure add much more to our hearing
experience, particularly in to sense pitch variations and pick
important sounds out of background noise.
* The safety and effectiveness of the FSP speech coding strategy has not been established in pre-lingually deaf children. The FSP strategy should only be used by CI users with at least 6 months experience with the CIS+ or HD-CIS programming options, and who have the cognitive ability to choose among the speech coding strategy options provided in the MAESTRO 2.0.1 software. All other cochlear implant patients should be fit with CIS+ or HD-CIS programming options.
Speech Processors 
