ABSTRACT
In a clinical setting, the loss of normal hearing function can most easily be described by two metrics: hearing thresholds and masking level. Hearing loss produces increased threshold levels, and the increases in threshold level that result from hearing loss can be frequency specic. Audiologists oen view a patient’s thresholds in the form of an audiogram, which plots frequency-specic hearing thresholds that are measured using pure-tone sinusoids at a range of frequencies. Oen, audiometric testing focuses on the range of frequencies most critical for speech understanding (250 Hz-8 kHz). e second metric that is useful for describing hearing loss is the masking level. Masking is a perceptual eect in which one stimulus “masks” a subsequent lower amplitude probe stimulus that is temporally or spectrally similar to the rst stimulus. Although masking levels are informative, the time required to measure them prevents their frequent use by audiologists, and they are more commonly used in research settings for device development. Oen, individuals suering from hearing impairments can be measured to have abnormal values of both threshold and masking level.
