Opening It Up!



This blog has forced me to go back over 10 years of development history with Crescendo – re-questioning everything that I had thought I knew. Some new discoveries were made along the way – e.g., Dual Engine mode.

But one of the left-over things in Crescendo from the earliest days was a very conservative approach in the interest of ear safety. And with more than 10 years experience behind us now, it is time to re-examine those safety limits.

We now have an audio dosimeter available to us, which we never had before. There is no longer any guessing about ear safety. We can actually measure our exposure levels.

So I went back into Crescendo’s algorithm and took out some of the more conservative stops. I found that by doing so, we opened up a tremendous space above 5 kHz. I can now hear the cymbals, high-hats, tambourines, shakers, triangles, etc, that had been in there but only a hint before. Now they stand right out to me. Not in your face, and I don’t think they were ever intended to be dominant sounds. But they are now definitely in there. I even get a sense of “air” that I never had before. The higher harmonics of piano notes are now more present, lending more of a bite to those sounds.

Another client states:

This new version is just stunning. I swear that I’m actually hearing “air” for the first time in years. I had forgotten what that sounds like but now I hear it again.  My subjective impression is that this version is getting rid of some high frequency distortion and extending the high frequency response upwards, possibly above 10 kHz. Of all the improvements you’ve made, this one has the biggest “wow factor” for me. It even makes Single Engine mode sound distinctly better to me.”

I find that my audio exposure is increasing, however. My dosimeter now shows on average about 4% per hour accumulated maximum daily audio dose. Sometimes less, sometimes more, depending on the genre.

My hearing theory shows that it is the mechanics of sound exposure that leads to accumulating hearing damage, whether you can hear those sounds or not. My own hearing with vTuning = 60 dB is pretty bad. But now I can hear that top octave (top for me!) from 5-10 kHz. The meters show that I’m being hit by a pretty loud sound up there, around 83-85 dBSPL, even though it sounds very comfortable to me. That’s why I keep an eye on my dosimeter. But, so far, I’m safe for up to 12-16 hours / day at these new levels.

I also found that attempting to correct any recruitment curves above the 75 dB threshold elevation was nigh impossible. Those recruitment curves are so steep near their threshold levels that you either hear nothing (below threshold) or vastly too much (above threshold), for presentation level variations as small as 0.1 dB. They are simply not controllable. So we no longer bother with them.

While frequencies with sensitivities above 75 dB threshold elevations are not quite profoundly lost, there really isn’t much you can do with them. By ignoring those extreme correction channels, the results for the rest of us are so much better than before.

It is an astonishing experience to hear so well again. All of my albums and recordings sound new to me again.

  • DM

Author: dbmcclain

Astrophysicist, spook, musician, Lisp aficionado, deaf guy

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