Programmable artificial ear incorporating desk-top scientific computer

Abstract

Sound-pressure recordings made in real-ear simulators are more realistic than those made in 2-cc couplers. Unfortunately, most real-ear simulators (1) require factory calibration and (2) were designed to simulate only the mean acoustic impedance of normal adult ears. Due to variability of ear-canal geometry and eardrum impedance among subjects, the statistical possibility of any one subject exhibiting such “mean” characteristics—especially if that subject has a conductive pathology—is very remote. Reported herein is the development of a programmable artificial ear (PAE) which (1) requires no factory calibration and (2) can be programmed to account for individual variations in source impedance, ear-canal geometry, and eardrum impedance. The PAE consists of a 2-cc coupler, microphone, amplifier, and desk-top scientific computer, equipment which is included in most laboratory/clinic inventories. Sound pressures recorded in the 2-cc coupler are adjusted via the computer to what they would have been had the recordings been made in a particular subject's ear. Good agreement has been obtained between PAE data and real-ear simulator measurements.