Models for pure tone audiometry enabling computational evaluation: Introduction to Japanese extensive experiences

Pure tone audiometry including “masking” is the most basic test in audiological medicine. Masking is based on theoretical models of sound perception and propagation and has been widely discussed since the 1950s. In Japan, such discussion has been conducted extensively, starting from early periods up to recent times, with success to enable mathematical simulation, but the achievements have little been disclosed to the English-speaking world. Here, Japanese experiences are introduced with explicit theoretical derivation from “Grand Principles (GPs)” appropriate for learning the basics of masking. Two models, Standard Masking Model and Extended Masking Model, are explained in detail with variables classified into three categories to avoid common misunderstandings. In particular, a smart heuristic method called “ABC” method, which makes excellent use of “sufficient masking” and “overmasking (cross-masking)”, is presented with computerized evaluation for its accuracy. The author hopes that this article will serve as a common basis for discussion among researchers and as a theoretical introduction for those motivated to learn masking.