Background: The Listening in Spatialized Noise–Sentences test (LiSN-S®) was originally developed
in Australia to assess auditory stream segregation skills in children with suspected
central auditory processing disorder (CAPD). The software produces a three-dimensional
auditory environment under headphones. A simple repetition-response protocol is utilized
to determine speech reception thresholds (SRTs) for sentences presented from 0 degrees
azimuth in competing speech. The competing speech (looped children's stories) is manipulated
with respect to its location (0 degrees vs. +90 degrees and −90 degrees azimuth) and
the vocal quality of the speaker(s) (same as, or different to, the speaker of the
target stimulus). Performance is measured as two SRT and three advantage measures.
The advantage measures represent the benefit in dB gained when either talker, spatial,
or both talker and spatial cues combined are incorporated in the maskers.
Purpose: The objective of this research was to develop a version of the LiSN-S suitable for
use in the United States and Canada. The original sentences and children's stories
were reviewed for unfamiliar semantic items and rerecorded by native North American
speakers.
Research Design: In a descriptive design, a sentence equivalence study was conducted to determine
the relative intelligibility of the rerecorded sentences and adjust the amplitude
of the sentences for equal intelligibility. Normative data and test–retest reliability
data were then collected.
Study Sample: Twenty-four children with normal hearing aged 8 years, 3 months, to 10 years, 0 months,
took part in the sentence equivalence study. Seventy-two normal-hearing children aged
6 years, 2 months, to 11 years, 10 months, took part in the normative data study.
Thirty-six children returned between two and three months after the initial assessment
for retesting. Participants were recruited from sites in Cincinnati, Dallas, and Calgary.
Results: The sentence equivalence study showed that post-adjustment, sentence intelligibility
increased by 18.7 percent for each 1 dB increase in signal-to-noise ratio. Analysis
of the normative data revealed no significant differences on any performance measure
as a consequence of data collection site or gender. Inter- and intra-participant variation
was minimal. A trend of improved performance as a function of increasing age was found
across performance measures, and cutoff scores, calculated as two standard deviations
below the mean, were adjusted for age. Test–retest differences were not significant
on any measure of the North American (NA) LiSN-S (p ranging from .080 to .862). Mean test–retest differences on the various NA LiSN-S
performance measures ranged from 0.1 dB to 0.6 dB. One-sided critical difference scores
calculated from the retest data ranged from 3 to 3.9 dB. These scores, which take
into account mean practice effects and day-to-day fluctuations in performance, can
be used to determine whether a child has improved on the NA LiSN-S on retest.
Conclusions: The NA LiSN-S is a potentially valuable tool for assessing auditory stream segregation
skills in children. The availability of one-sided critical difference scores makes
the NA LiSN-S useful for monitoring listening performance over time and determining
the effects of maturation, compensation (such as an assistive listening device), or
remediation.
Key Words Auditory stream segregation - (central) auditory processing disorder
