In Brief:
There is considerable interest in the use of cortical event-related potentials (ERPs), especially MMN, for assessing populations where behavioral measures of speech detection and discrimination are difficult to obtain (e.g., infants, young children, and difficult-to-test patients). These potentials have shown promising, though preliminary, results in assessing benefit from sensory aids and monitoring of an individual's progress with auditory training. This study aimed to investigate systematically the effects of sensorineural hearing loss on cortical event-related potentials and their associated behavioral measures (d sensitivity and reaction-time) to the speech sounds /ba/ and /da/. Both ERP amplitudes and behavioral discrimination (d) scores were lower for listeners with sensorineural hearing loss than for those with normal hearing, but this effect was evident only for listeners with more pronounced hearing impairment. In contrast, prolongations in the ERP and behavioral latencies, relative to responses from normal-hearing subjects, began with even mild threshold elevations. The results indicate that latency measures are more sensitive indicators of the early effects of decreased audibility than are response strength (amplitude, d, or percent correct) measures.
