Comparison between observed and estimated masked thresholds.

<p>Observed and estimated masked thresholds (in dB SPL) were compared for each masker type, for all target frequencies and spatial conditions. The first four columns show the estimated and the observed masked thresholds as mean absolute values (in dB SPL) ± standard deviation. The last two columns show the estimated and the observed amounts of spatial release from masking (SRM) in dB that were calculated by subtracting the thresholds of the spatially separated conditions from the thresholds of the co-located conditions. Mean values for the observed thresholds were calculated from five individuals. Mean values for the estimated thresholds were calculated from 51 subjects of the LISTEN HRTF database <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0026124#pone.0026124-Warusfel1" target="_blank">[13]</a>. Details about the estimation of the thresholds can be found in the section <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0026124#s2" target="_blank">Materials and methods</a>: Model description.</p

Amount of spatial release from masking for each masker type.

<p>Amount of spatial release from masking (difference between co-located and spatially separated configuration) for the 1 kHz target frequency (grey, squares) and for the 8 kHz target frequency (black, triangles) for each masker type. Error bars represent the standard deviation.</p

Statistical results of the four planned contrasts for each of the four subgroups.

<p>A repeated measure ANOVA with planned contrasts was performed for each of the four subgroups and the F-value, the p-value and the effect size partial eta squared are displayed for each contrast. Details about the underlying hypotheses can be found in the results section.</p

Mean observed masked thresholds for each masker type.

<p>Mean masked thresholds from five individuals for the detection of a pure tone target in each of the five masker types are displayed in absolute values (in dB SPL). Thresholds are shown for the co-located configuration (filled symbols) and for the spatially separated configuration (open symbols) separated by the target frequency (left panel = 1 kHz, right panel = 8 kHz). Error bars represent the standard deviation (SD). The five masker types used in this experiment are: “Harm” = a harmonic masker, “Mistuned” = a harmonic masker with an inharmonic relation to the target frequency, “Inh/Sess” = inharmonic per session, i.e. a random frequency composition redrawn for each session, “Inh/Pres” = inharmonic per presentation, i.e. a different random frequency composition for each stimulus presentation, “Noise” = bandpass noise.</p

Schematic drawing of the five masker types used in the experiment.

<p>Schematic drawing of the five masker types (grey) in the two frequency regions used in the experiment as indicated on the ordinate. “Harm” = harmonic complex, “Mistuned” = mistuned compared to target, “Inh/Sess” = inharmonic, frequencies varied per session, “Inh/Pres” = inharmonic, frequencies varied per stimulus presentation, “Noise” = bandpass noise. See text for further explanations of the maskers. Target signals were 1 or 8 kHz pure tones, respectively (black).</p