Nisha Kavassery Venkateswaran, Kumar Ajith Uppunda
Department of Audiology, All India Institute of Speech and Hearing, Naimisham Campus, Mysore, India.
J Audiol Otol. 2022 Jul;26(3):113-121. doi: 10.7874/jao.2021.00451. Epub 2022 Feb 24.
This study compared the effectiveness of two spatial training programs using real and virtual sound sources in refining spatial acuity skills in listeners with normal hearing.
The study was conducted on two groups of 10 participants each; groups I and II underwent spatial training using real and virtual sound sources, respectively. The study was conducted in three phases: pre-training, training, and post-training phases. At the pre- and post-training phases, the spatial acuity of the participants was measured using real sound sources through the localization test, and virtual sound sources through the virtual acoustic space identification (VASI) test. The thresholds of interaural time difference (ITD) and interaural level difference (ILD) were also measured. In the training phase, Group I participants underwent localization training using loudspeakers in free field, while participants in Group II were subjected to virtual acoustic space (VAS) training using virtual sound sources from headphones. Both the training methods consisted of 5-8 sessions (20 min each) of systematically presented stimuli graded according to duration and back attenuation (for real source training) or number of VAS locations (for virtual source training).
Results of independent t-scores comparing the spatial learning scores (pre vs. post-training) for each measure showed differences in performance between the two groups. Group II performed better than Group I on the VASI test, while the Group I out-performed Group II on the ITD. Both groups improved equally on the localization test and ILD.
Based on the present findings, we recommend the use of VAS training as it has practical implications due to its cost effectiveness, need for minimal equipment, and end user usefulness.
本研究比较了使用真实声源和虚拟声源的两种空间训练方案在提高听力正常的聆听者空间敏锐度技能方面的有效性。
该研究针对两组各10名参与者展开；第一组和第二组分别使用真实声源和虚拟声源进行空间训练。研究分三个阶段进行：训练前、训练和训练后阶段。在训练前和训练后阶段，通过定位测试使用真实声源测量参与者的空间敏锐度，并通过虚拟声学空间识别（VASI）测试使用虚拟声源进行测量。还测量了耳间时间差（ITD）和耳间声级差（ILD）的阈值。在训练阶段，第一组参与者在自由场中使用扬声器进行定位训练，而第二组参与者使用来自耳机的虚拟声源进行虚拟声学空间（VAS）训练。两种训练方法均包括5 - 8节课程（每节20分钟），根据持续时间和反向衰减（针对真实声源训练）或VAS位置数量（针对虚拟声源训练）系统呈现分级刺激。
比较各测量指标的空间学习分数（训练前与训练后）的独立t分数结果显示两组在表现上存在差异。第二组在VASI测试中的表现优于第一组，而第一组在ITD方面优于第二组。两组在定位测试和ILD方面的改善程度相同。
基于目前的研究结果，我们建议使用VAS训练，因为它具有成本效益、所需设备最少且对最终用户有用等实际意义。
