resound hearing aid theory as i understand it the following is based on copies i was given of some articles published in hearing instruments i would appreciate any comments about this and other new technology for hearing aids the resound system was developed on the basis of some research at at t and appears to take a different approach from other aids it appears to me that a new programmable aid like the widex just uses a more flexible and programmable version of the classical approach of amplifying some parts of the spectrum more than others and adding some compression to try and help out in noisy situations the major difference in the resound approach is that it divides the spectrum into low and high frequencies splitting point is programmable apparently based on the fact that lots of vowel information can be found in the low frequencies while the important consonant information unfortunately for me is in the high frequencies the two bands then are treated with different compression schemes which are programable they have also developed a new fitting algorythm that builds on what they call abnormal growth of loudness this latter is interesting and fits my own personal experience though i think the phrase is missleading what appears to be the case is that as you exceed the minimum threshold for a person with hearing loss the deficit becomes progresslively less compared to normals and by the time you reach the too loud point the sensitivity curves appear to converge this means that if you just boost all sound levels you are overloading at the high end for people with hearing losses hence what you want is progressively less amplification as the signal get closer to the maximum tolerable point you want to boost low volume sounds more than high and do so potentially differently for the low and high frequency parts of the spectrum specially for someone like me who is relatively normal up to cps and then falls off a cliff aids with simple compressors don t descriminate between energy in the low and high frequencies and can therefor compress useful high frequency information because of high volume of low frequency components particularly impressive was the resound performance with whispered speech and in simulated restaurant noise situations rich haller rhaller ns uoregon edu university of oregon eugene or usa
