 The National Acoustic Laboratory has developed two generations of prescription procedures for fitting wide dynamic range compression, WDRC, instruments. The first generation, NALNL1, was introduced in 1999 and focused on improving speech intelligibility and overall loudness comfort. The second generation, NALNL2, builds upon the successes of NALNL1 while incorporating new data and theoretical components to optimize performance. This article was authored by G. Keitzer, H.R. Dillon, M. Flax, and others.