Effects of frequencies of inaudible high-frequency sounds

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K00376
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Kansei informatics
• Research Institution: Edogawa University (2017-2018); Jumonji University (2016)
• Principal Investigator: Fukushima Ariko 江戸川大学, 基礎・教養教育センター, 講師 (30523823)
• Co-Investigator(Kenkyū-buntansha): 仁科 エミ 放送大学, 教養学部, 教授 (20260010)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: ハイパーソニック・エフェクト / 超音波 / 自発脳波

Outline of Final Research Achievements

Hypersonic effect is a phenomenon in which sounds rich in super high frequencies above the upper limit of the audible range enhance the activity of the basic brain including the interbrain and midbrain and activate the mind and body. In this phenomenon, the fundamental brain activity is enhanced when the super high frequency of higher frequency than the frequency at around 32 kHz to 40 kHz coexists with the audible sound, while the activity is decreased when the lower component coexists. In this research, we created a sound source for presentation in which the super-high frequency, making the bandwidth narrower from the previous 8 kHz width to 4 kHz width, and examined at what frequency the boundary of the frequency band that leads to improvement or decrease of the fundamental brain activity by observing EEG, which is considered as an index, showing a positive correlation with fundamental brain activity.

Free Research Field

情報環境学

Academic Significance and Societal Importance of the Research Achievements

深部脳活性を高めうる周波数帯域を十分含み、その低下を導きうる周波数帯域をできるだけ抑制したデジタルオーディオコンテンツを実現することは、今後の音楽メディアにとって重要といえる。この基幹脳活性との関係で考慮すべき再生周波数帯域に関する研究成果は、音楽配信、放送、パッケージ・コンテンツおよびそれら音響の収録・編集・再生機材の仕様策定に直結する大きな学術的・応用的意義を有する。