Biomedical subjects

Madhu B Dev

Publications and source records attributed to Madhu B Dev.

3 recordsLinked to original sources

PubMed2004

Developmental effects in the masking-level difference.

Adults and children (aged 5 years 1 month to 10 years 8 months) were tested in a masking-level difference (MLD) paradigm in which detection of brief signals was contrasted for signal placement in masker envelope maxima versus masker envelope minima. Maskers were 50-Hz-wide noise bands centered on 500 Hz, and the signals were So or Sp 30-ms, 500-Hz tones. In agreement with previous studies, it was found that MLDs were greater for masker envelope minima placement than for masker envelope maxima placement. Across the age range of the children tested here, the binaural advantage associated with the masker envelope minima increased with the age of the child. One interpretation of the present results is that there is a developmental improvement in binaural temporal resolution over the age range tested here.

Acoustic Stimulation↗

PubMed2003

The effect of otitis media with effusion on perceptual masking.

OBJECTIVE: To determine the effect of otitis media with effusion (OME) on perceptual masking (a phenomenon in which spondee threshold for a 2-talker masker is poorer than for a speech-shaped noise masker). DESIGN: Longitudinal testing over a 1-year period following insertion of tympanostomy tubes, using clinical and normal-hearing control groups. SUBJECTS: Forty-seven children having a history of OME were tested. Possible testing intervals were just before the placement of tympanostomy tubes, and up to 3 separate occasions after the placement of the tubes. An age-matched control group of 19 children was tested. METHODS: A perceptual masking paradigm was used to measure the ability of the listener to recognize a spondee in either a speech-shaped noise or a 2-talker masker background. The masker was either continuous or gated on and off with the target spondee. RESULTS: In gated masking conditions, children with a history of normal hearing showed only slight perceptual masking, but the children with a history of OME showed relatively great perceptual masking before surgery and up to 6 months following surgery. In continuous masking conditions, both groups of children showed relatively great perceptual masking and did not differ significantly from each other in this respect either before or after surgery. However, before surgery, the OME group showed higher thresholds in both the 2-talker and speech-shaped noise maskers. CONCLUSIONS: In agreement with previous psychoacoustical findings, the relatively great perceptual masking in gated conditions shown by children with OME history may reflect a general deficit in complex auditory processing.

Age Factors↗

PubMed2002

Spondee recognition in a two-talker masker and a speech-shaped noise masker in adults and children.

OBJECTIVE: The objective of the study was to examine developmental effects for perceptual masking due a two-talker masker. Both continuous and gated maskers were employed in order to determine the importance of masker continuity for perceptual masking. DESIGN: A repeated measures design compared the spondee recognition performance of adults and children using both a speech-shaped noise and a two-talker masker. The masker was either presented continuously, or was gated on and off at about the same time as the target spondee. The ages of the listeners were 19 to 48 yr (adults) and 5 to 10 yr (children). RESULTS: The results for the continuous masker indicated higher thresholds for the two-talker masker than for the speech-shaped noise masker. This effect was greater in the children than in the adults. In the gated masking condition, the greater masking effect associated with the two-talker masker was either diminished (children) or eliminated (adults). CONCLUSIONS: These results suggest a masking effect for two-talker speech competition that is greater in children than in adults. Perceptual masking is greater for continuous than for gated masking.

Adult↗