High-resolution audio has a higher sampling frequency and a greater bit depth than conventional low-resolution audio such as compact disks. The higher sampling frequency enables inaudible sound components (above 20 kHz) that are cut off in low-resolution audio to be reproduced. Previous studies of high-resolution audio have mainly focused on the effect of such high-frequency components. It is known that alpha-band power in a human electroencephalogram (EEG) is larger when the inaudible high-frequency components are present than when they are absent. Traditionally, alpha-band EEG activity has been associated with arousal level. However, no previous studies have explored whether sound sources with high-frequency components affect the arousal level of listeners. The present study examined this possibility by having 22 participants listen to two types of a 400-s musical excerpt of French Suite No. 5 by J. S. Bach (on cembalo, 24-bit quantization, 192 kHz A/D sampling), with or without inaudible high-frequency components, while performing a visual vigilance task. High-alpha (10.5–13 Hz) and low-beta (13–20 Hz) EEG powers were larger for the excerpt with high-frequency components than for the excerpt without them. Reaction times and error rates did not change during the task and were not different between the excerpts. The amplitude of the P3 component elicited by target stimuli in the vigilance task increased in the second half of the listening period for the excerpt with high-frequency components, whereas no such P3 amplitude change was observed for the other excerpt without them. The participants did not distinguish between these excerpts in terms of sound quality. Only a subjective rating of inactive pleasantness after listening was higher for the excerpt with high-frequency components than for the other excerpt. The present study shows that high-resolution audio that retains high-frequency components has an advantage over similar and indistinguishable digital sound sources in which such components are artificially cut off, suggesting that high-resolution audio with inaudible high-frequency components induces a relaxed attentional state without conscious awareness.
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机译：与传统的低分辨率音频（例如光盘）相比，高分辨率音频具有更高的采样频率和更大的位深度。较高的采样频率可以再现在低分辨率音频中被切掉的听不见的声音成分（20 kHz以上）。以前对高分辨率音频的研究主要集中在这种高频分量的影响上。众所周知，当存在不可听见的高频成分时，人脑电图（EEG）中的α波段功率会比不存在时更大。传统上，阿尔法带EEG活动已与唤醒水平相关联。但是，以前没有研究探讨具有高频成分的声源是否会影响听众的觉醒水平。本研究通过让22名参与者收听JS Bach的法式5号法国套房的400年代音乐摘录的两种类型（采用Cembalo，24位量化，192 kHz A / D采样）来检验这种可能性，有无听不见的高频成分，同时执行视觉警戒任务。具有高频分量的摘录的高α（10.5–13 Hz）和低β（13–20 Hz）的脑电图功率比没有高频分量的摘录更大。反应时间和错误率在任务期间没有变化，并且摘录之间没有差异。对于具有高频分量的摘录，警惕任务中目标刺激引起的P3分量的幅度在侦听期的后半段增加，而对于其他没有摘录的摘录，没有观察到这种P3幅度变化。参与者在音质方面没有区分这些摘录。聆听后对高频成分的摘录仅对主观的不活跃的愉悦感的主观评分高于其他摘录。本研究表明，保留高频成分的高分辨率音频优于类似且难以区分的数字声源，在后者中，人为地将此类成分切断，这表明带有高频成分的音频听不见，从而引起了放松的注意力。没有意识的状态。
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