Re: ADRO as superior technology: No. It is not superior… it is simply another way of handling the problem of sounds being too loud for comfort. The vast majority of the mfg’s and dispensers prefer the WDRC method of handing loud sounds. Here is why.
Virtually 100% of the persons suffering most of the common severe forms of hearing loss also suffer some degree of recruitment. That is, loud sounds distort and cause discomfort. (reduced dynamic range)
The ADRO system is designed to slowly (slowly is a direct quote from the Dynamic Hearing professional instruction manual.) change gains to handle loud sounds (and too soft sounds). Typically gains change at the rate of 3db/second up to 9db/second. This rate is far too slow to control the loud transient sounds encountered in everyday life. So ADRO relies on a standard MPO (Maximum Power Output) circuit to catch the fast loud transients. MPO circuits generate distortion directly proportional to the amount of reduction required…in essence MPO’s are loudness clippers. They do not do a good job when pushed too far.
What this means is that ADRO is an excellent system for those with mild to moderate loss with a minimum of recruitment. It is not suitable for some of those with moderate loss and all of the severe/profound losses because of the usual accompanying recruitment.
WDRC aids handle loud transients by several methods. The fast and slow compression circuit (syllabic+dual) with adjustable knee point, often some form of sound smoothing in the pre amp stages and as a last resort a maximum output limiter. WDRC aids can be very flexible and can be adjusted to work satisfactorily with a wide variety of loss types. (syllabic=1 to 3 milliseconds…dual= .3 to 1 second)
For those with lots of recruitment WDRC is the way to go. Ed