Monaural low-redundancy speech tests: Assessment of monoaural separation/closure

Abstract

Monaural separation and closure are auditory processing mechanisms that allow to maintain significant communicative interactions in real environments, with adverse acoustic conditions, competitive noise and non-ideal speakers. These skills depend on intrinsic redundancy, which is determined by the structures and physiology of the central auditory nervous system, and extrinsic redundancy, which is determined by the acoustic, linguistic and contextual cues of the auditory signal. These processes have been assessed through different forms of degradation of extrinsic redundancy, giving rise to three test categories: low-pass filtered speech tests, speech in noise tests and time-compressed speech tests. Speech in noise tests have become popular in recent years, however, all three categories have documentation to support their usefulness, are available in Spanish and can be applied to both children and adults. Although some have established normative values, it is necessary to interpret the results considering their ecological validity and some variables such as schooling, socioeconomic status and other social determinants of health that could influence performance.