Introduction to three current hearing aid fitting methods

The three hearing aid prescription procedures most frequently used in the United States are summarized: POGO, the Berger Method, and the NAL Method. The gain portion of each of the three is based upon a modification of the 1/2 gain rule, which was originally published by Samuel F. Lybarger. The three methods differ in the number of test frequencies involved and on the amount of gain prescribed at the various frequencies. The Berger and NAL procedures incorporate the speech spectrum in their gain-frequency response formulas. With two representative threshold patterns, POGO and the Berger Method produced a higher Articulation Index than the NAL Method.