Excellent overview of what goes on in the most sophisticated piece of audio processing gear any of us will ever have the opportunity to use! Since I am a doctoral-candidate audiologist, and an auditory researcher at Columbia University, I can tell you it gets much more fascinating (and even weirder!) than anything you have touched upon here. But that is a topic for another day.

I first wish to thank you for giving our sense of hearing the well-deserved respect and mention that it so deserves. It is an often-overlooked component of the signal chain in our discussions of gear and signal processing. Unfortunately, it is also too often abused. Everyday I see the effects of the noisy world we live in on the human ear. I am referring not only to the loss of hearing sensitivity, but also the loss of frequency specificity in the cochlea (think psychophysical tuning curves here) resulting from inner hair cell damage, which is very difficult to rehabilitate.

Hearing loss is easy to prevent, yet once the damage has been inflicted, there is (usually) no going back. It is simply gone. There is some promising early work in the area of hair-cell regeneration (at least 20 years off even by the most optimistic estimates) as well as various therapies centered on the concept of pharmacologic prophylaxis, including N-acetylcysteine, and the more mundane vitamin C. However, the pharmacological therapies are still unproven, and are very controversial.

As audio professionals, part of your overall healthcare should include annual hearing tests, including Distortion-Product Otoacoustic Emissions (DPOAEs), even if your audiogram is “normal.” Up to 25% of your outer hair cells can be obliterated before a hearing loss will be evident on a basic audiogram, and DPOAEs are highly sensitive to this early damage. Early detection is the key concept here. Also, try to monitor at conservative levels (less than 85 dB SPL is good), and whenever this is not possible use custom – molded musician’s earplugs (especially for live sound work).

Did you finish the article? You have me on the edge of my seat! Please, don't let me fall off!! Where are the answers to those great questions you had??

Oops! Thanks for bringing this to my attention! We're missing a couple of pretty good articles.

The next article in the series is The Audio Window, which is here. Following that are two articles: "Hearing: the Highs and Lows of It" and "Hearing: the Louds and Softs of It." I will get webguy to get these included ASAP. In the meantime, you can download these from

http://moultonlabs.com/berklee/

I hope this helps.

Best regards,

Dave

Thanks for the quick reply. =)

It will take me a while to get through everything, but I'm sure it will time well spent. Awesome.