Data from: Development of sound localization strategies in children with bilateral cochlear implants

Stimulus WAVE Files used in localization taskStimuli consisted of bi-syllabic Children’s Spondees that have been previously used for studies on spatial unmasking of speech in children with NH [14], and with BiCIs[15], recorded with a male voice at a sampling rate of 44 kHz. The speech corpus had 25 words. On each trial one of the words was randomly chosen from the list, with replacement. Thus, on any given trial the stimulus was unpredictable, thereby reducing the availability of reliable spectral cues that might be used in the computation of sound source location. Stimuli were balanced for loudness using equal root-mean-square levels for all words. Stimuli were amplified and sent to the loudspeakers via Tucker Davis Technologies System III hardware. Stimulus levels averaged 60 dB SPL, with a random variation between 56 and 64 dB SPL (±4 dB) from trial to trial to minimize the availability of overall level cues.Stimulus Files.zipMatLab code used to calculate and plot Localization SensitivityAnalyses of localization sensitivity employed a statistical non-parametric Kruskal-Wallis test to examine the relative independence of responses to each stimulus location, given a single response to an unknown stimulus. For each pair of locations in the loudspeaker array, the two response groups were analyzed using pairwise localization sensitivity index (LSI) values based on the z-scores from the p-value obtained bythe non-parametric Kruskal-Wallis test. The analysis produces a matrix of LSIs in coordinates of response locations. For N=15 target locations, the total number of LSI values was 105 [15*(15-1)/2=105]. The matrix is symmetrical about the diagonal. The matrixwas interpolated via the MATLAB contour function to find a contour of LSI with a z score of 1.65 (the 95th confidence level as the statistical threshold indicative of two locations being perceptually differentiated). We defined the contour of LSI = 1.65 as the sensitivity threshold. The overall localization sensitivity (LS) was characterized for individuals by averaging LSIs in the LSI matrix.analysis.txt