Aaron R. Thornton
Audiol. Dept., Mass. Eye and Ear Infirmary, 243 Charles St., Boston, MA 02114
Routine clinical application of the articulation index (AI) has been reported previously [A. R. Thornton et al., ASHA 34, 148 (1992); Z. Hou et al., ASHA 35, 234 (1993); Z. Hou and A. R. Thornton, Ear Hear. 15(2) (1994)]. This paper reports further development of an AI-based clinical model for evaluating hearing loss and hearing aids and for maximizing hearing aid performance across listening conditions. AIs across a range of listening conditions are plotted on a series of two-dimensional graphs to provide visual evaluations of a patient's residual speech ability under each condition with or without a hearing aid. The AIs are integrated to obtain an integrated articulation index (IAI) as a criterion measure for evaluating the overall speech ability across the conditions. The optimal IAI is suggested as a hearing aid prescription method. An audibility improvement index based on the IAI is introduced to evaluate the benefit a patient might gain from using a hearing aid. This model can address loss and amplification requirements in both quiet and noise conditions and provides a comprehensive and easy-to-use tool for routine clinic applications.