Hypersonic Sound Environment

The inaudible sound that support human health in the rich environment


Normally human beings can listen to the sound which is lower than 20,000 Hz and the sound frequencies above the human audible range are called hypersonic sound or ultrasonic sound.

The research by expert researchers has revealed that human beings receive this hypersonic sound through receptors on the skins and they are effective in improving immunity, reducing stress, and fostering our human original sensitivity such as feeling the beauties of things.


One of the leading experts on hypersonic sound effect research is Shoji Yamashiro. He has investigated the possibility of this inaudible sound in the tropical rainfall forest especially in Bali island and found that there are rich hypersonic sound in the rich diverse forest. Later, some more researchers are following further research such as Manabu Honda from National Center of Neurology and Psychiatry.


Regreen has investigated hypersonic sound environments in the forests, thatched field, satoyama environments, traditional music in Japan and abroad, traditional works for architecture, and so on. We are using the possibilities of the effect for design of architectural, landscape, and urban environments.


We show examples of investigation of hypersonic sound below.


Harvesting thatch

We found that hypersonic sound exceeding 180,000 Hz are emitted from the sound of the “zak-zak-zak-zak” when harvesting thatch with a sickle. Other hypersonic sound is also emitted when touching the thatch and working of the thatch. The work for harvesting roofing materials also helps to regulate people’s mental and physical health, and it can truly be said to kill two birds with one stone. In addition, annual thatch harvesting improves the condition of the soil and the quality of the thatch, making it easier for thatch mice, insects, and other living creatures to grow and creating a good environment for everyone.


Thatch-roofing work
Rethatching work of thatched roofs consists of various processes and operations, but we found that hypersonic sound are emitted from most of the operations where thatch is handled by hands and tools. In particular, the more skilled the person was, the higher the hypersonic sound was emitted in the work of aligning the tips of the thatch using a tool called a tataki and in the work of trimming and aligning the tips of the thatch with shears. We found that a pleasant sound is emitted from the work of skilled craftsmen, and that this can also be said from hypersonic sound point of view.

Conch Shell Trumpet


Traditional instruments such as Japanese Taiko Drums and Japanese Shakuhachi Bamboo Flute often emit hypersonic sound, but we found that strong hypersonic sound is also emitted from Conch Shell Trumpet. The sound of the conch, used in the mountain ascetic practices, ceremonies and during warfare and said to be able to reach up to 2 km away, was found to have a calming, healing, and immune-boosting effect on people. It is highly likely that our ancestors understood such effects even in the absence of scientific data and used them in religious settings to heal people’s minds.



Thus, hypersonic sound is often emitted from instruments used in traditional work and religious occasions, and what our ancestors have cultivated shows that there has been a function since ancient times to heal people’s hearts, boost immunity, and activate the human natural sensitivity. It is not something that has been separated from each work, religious rituals, and events, but has existed as a form, and it could be said that it is something emanated from the earth itself, and human found it and form it.

For example of application the research findings to the design, please refer below.



One Health Forest


For detail information about this research and proposal, please feel free to contact us.