Masking-level differences and the form of the psychometric function

Functions showing the relation between-the detectability and the energy of a signal were determined for various interaural phase conditions. The empirical relation between d′ and signal energy E is approximately d′=m(E/N₀)^k where m and k are constants for a particular function. The data show that k is fairly constant for a particular O and that m depends upon the interaural condition. That is, the various psychometrie functions for a given O all had the same form, independent of location. Therefore, the magnitude of the MLD=(10/k)log(m_i/m_r), where m_i is the constant for condition i, and m_r corresponds to a reference condition. Consequently, an MLD is relatively independent of the level of performance that is chosen for the determination of that MLD.