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I spent several hours refining the GUI. Apple has now implemented a constraint based layout system, to accommodate iPads, iPhones, iWatches, and iMacs. I only care about iMac. At any rate, I finally succeeded, and produced a fresh GUI for Crescendo. The DSP processing incorporates the latest research findings.

I find myself leaning more and more toward the use of custom audiology corrections instead of the single-knob vTuning. I have developed a noticeable Left/Right imbalance in the 1-2 kHz region. And vTuning treats your ears as equals. So I am now beyond that point.

I am nearly 71 years old now. My paternal grandmother was deaf as a doorknob in her final years. And my father’s oldest brother was likewise very deaf. He was a professional musician and Professor of Music for Brooklyn College before he retired. He seemed to me like he had severe conduction losses. Sadly, no amount of Crescendo could help him.

So perhaps my genetic loading and my advancing age is producing these changes. I still use Crescendo for hours on end, every single day. I could not bear to live without it.

If anyone wants an updated version of Crescendo, just drop me a note.

Current processing specifications:

– 11 Channels of nonlinear compression processing in each of Left/Right channels. Each channel is 2.5 Bark wide, together spanning the entire audio spectrum from 20 Hz to 20 kHz.

– Channel filtering takes into account the asymmetry of cochlear frequency response at any frequency. These are much more than just simple triangular bandpass filters.

– Sample rates of 44.1, 48, 88.2, and 96 kHz are supported. I use mostly 48 kHz.

– Switchable between single-knob vTuning mode, and custom audiology. For the audiology, you could start with your last professional measurements, and then start hacking away. (Those professional measurements are likely wrong, since they don’t even understand their own zero point.) So start with those, and begin increasing by 5 dB increments till it begins to sound correct.

– The custom audiology also allows for Decruitment and HyperRecruitment corrections in Phons space. Use positive amounts for Decruitment, and negative amounts for HyperRecruitment. (See pic above for my own settings). There are no diagnostic tests to determine the amounts for Decruitment nor HyperRecruitment. You just have to set these by trial and error. I find that using increments of 1 dB is best for these Phons corrections.

– Processing is limited for ear safety reasons. So even if you indicate that you have 70 dB of threshold elevation, remember that was for threshold level sounds. We don’t live in a threshold level world. So typically that channel would be receiving 12-20 dB correction boost at average musical levels in the treble region, which normally has very low power. At any setting, you will never be presented with more than 30 dB gain. And we use crest factor analysis to very quickly remove that gain on percussive impulses, using a 2 ms lookahead. So this does mean that severe impairments will lose the very lowest level signals. But ear safety takes priority here.

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Author: dbmcclain

Astrophysicist, spook, musician, Lisp aficionado, deaf guy