Comparison of a Free-Field and a Closed-Field Sound Source Identification Paradigms in Assessing Spatial Acuity in Adults With Normal Hearing Sensitivity.

BACKGROUND AND OBJECTIVES: Traditional sound field localization setups in a free-field environment closely represent real-world situations. However, they are costly and sophisticated, and it is difficult to replicate similar setups in every clinic. Hence, a cost-effective, portable, and less sophisticated virtual setup will be more feasible for assessing spatial acuity in the clinical setting. The virtual auditory space identification (VASI) test was developed to assess spatial acuity using virtual sources in a closed field. The present study compares the legitimacy of these two methods. SUBJECTS AND METHODS: Fifty-five individuals with normal hearing (mean age±SD: 21± 3.26 years) underwent spatial acuity assessment using two paradigms: 1) the sound field paradigm (localization test) and 2) the virtual paradigm (VASI test). Location-specific and overall accuracy scores and error rates were calculated using confusion matrices for each participant in both paradigms. RESULTS: The results of Wilcoxon signed-rank tests showed that the locationspecific and overall accuracy scores for both paradigms were not significantly different. Further, both paradigms did not yield significantly different localization error rates like right and left intra-hemifield errors, inter-hemifield errors, and front-back errors. Spearman's correlation analysis showed that all the measures of the two paradigms had mild to moderate correlation. CONCLUSIONS: These results demonstrate that both VASI and the sound field paradigm localization test performed equally well in assessing spatial acuity.

Polyol-assisted hydrothermal synthesis of Mn-doped α - Fe2O3(MFO) nanostructures: Spin disorder-induced magnetism and photocatalytic properties.

Hierarchical nanostructures play an important role in environmental clean-up and sustainability applications. The magnetic and photocatalytic characteristics of flower-like Mn-doped α-Fe2O3 nanostructures were prepared by using a polyol-assisted hydrothermal method. Crystallite sizes are in the range of 35-42 nm, and the existence of 3D hierarchical nanostructures was observed in FESEM pictures. The optical band gap energy varies between 2.08 and 2.16 eV, while XPS examination exposes the ions' charge states and validates Mn3+ inclusion in the Fe3+ lattice. At room temperature, the addition of Mn to α-Fe2O3 results in a spin disorder ferromagnetism and coercivity of about 600 Oe was achieved. Methylene blue (MB) dye solution degraded by 92% when 2.5% Mn doped with α-Fe2O3 under visible conditions for 120 min irradiation time.

Visible light photocatalytic and magnetic properties of V doped α-Fe2O3 (VFO) nanoparticles synthesized by polyol assisted hydrothermal method.

Vanadium-doped α-Fe2O3 nanoparticles (VFO nanoparticles) were prepared by polyol-assisted hydrothermal method. The impact on the structure, optical, magnetic and photocatalytic properties of α-Fe2O3 nanoparticles were studied by varying the vanadium concentration from 1 to 5%. XRD analysis confirms the presence of hematite phase with hexagonal structure and estimates the nanocrystals size as ∼26-38 nm. FESEM and TEM reveal the formation of 3D flower-like morphology bundled with 2D nanoflakes. The estimated band gap energy was in the range 2.01 eV-2.12 eV. XPS study shows the presence of vanadium in V4+ oxidation state in VFO nanoparticles. VSM study shows a non-saturated hysteresis loop with weak ferromagnetic behavior for all the VFO nanoparticles. 5% V doped α-Fe2O3 nanoparticles (5%VFO nanoparticles) exhibited superior visible light driven photocatalytic activity compared to other samples.