PERCEPTION OF VCV'S IN A FLUCTUATING NOISE ENVIRONMENT
Paul A. Howard‐Jones · 2024
Two experiments are described which investigate the intelligibility of a small set of spoken VCV's when presented in ucuiaLing noise environments to normally hearing subjects.The masking effecLs of three noise environments.which differ with respect to the time-scale of the uctuation of their power.are compared with those of white noise.The rust experiment compared the masking effectiveness of two samples of uctuating broadband noise with that of white noise.One of these samples was 'eubed noise whose power uctuated on an instantaneous time-scale.The other uctuating noise possessed random interruptions of 80 to was of milliseconds.The second experiment compared the masking characteristics of a sample of white noise with the same sample which is attenuated every other second.for a second.All the noise samples used in these experiments exhibited at long~term frequency spectra in both experiments.adaptive test procedures were used to determine the Spwch Reception Threshold (SRT) associated with each sample of noise.and percentagecorrect scores ever a range of S/N levels were used to plot Perfonnancevlntensity (Pl) functions.Results showed that.for this Speech material.instantaneous uctuations have little in uence upon masking effectiveness.whilst the two noises which uctuated over longer time-scales were less effective maskers than white noise (at the same r.m.s.).Thc third uctuating noise.whose r.m.s.changed every second.produced a attened PI function.The types of phonetic confusions associated with this noise were more random.and normally robust features, such as voicing, were more often undetected.