Home > News Release > 2012 > New Way of Transmitting Information by Audio Frequency Yamaha and Showa University School of Medicine Conclude Joint Research into Human Body’s Stress Response to INFOSOUND™

New Way of Transmitting Information by Audio Frequency
Yamaha and Showa University School of Medicine Conclude
Joint Research into Human Body’s Stress Response to INFOSOUND™

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Yamaha Corporation (Head Office: 10-1, Nakazawa-cho, Naka-ku, Hamamatsu, Shizuoka Prefecture, Japan; President: Mitsuru Umemura) announces that it has conducted joint research with Showa University (1-5-8 Hatanodai, Shinagawa-ku, Tokyo; President: Takashi Katagiri) into the effects on the human body of INFOSOUND, the Yamaha-developed means of transmitting digital information using the very high audio frequency sound range. Professor Seiji Shiota and Visiting Professor Kazue Sato of the Showa University School of Medicine’s Department of Anatomy I conducted the research, which verified that “INFOSOUND signals do not cause an unacceptable increase in stress at the volume levels normally used in communication.”

Background and Aims

Yamaha has been advancing the research and development of INFOSOUND acoustic information transmission technology since 2008. The transmission of information using sound waves has three main benefits in that they enable the use of conventional speaker equipment; the simultaneous delivery of data to multiple receivers (one-to-many data delivery); and control of the range of access by volume and speaker directionality. INFOSOUND is expected to have applications in a wide range of fields, including broadcasting, usage at shops and public facilities as well as incorporation into all kinds of digital signage and music CDs. As acoustic communication will come into wider use going forward, it is only natural that there should be requirements that the sound signals used not have an adverse effect on the human body. The 18.6kHz–20.6kHz frequencies normally used with INFOSOUND are inaudible to the majority of people. Furthermore, the communication technology is based on a form of spread-spectrum system (diffusing and transmitting digital signals in a broader band) that requires a lower volume for communication when compared with other acoustic information transmission technology. In light of the variety of past research results and documents on the subject, it is thus considered that there exists no possibility of any harmful physical effect on the auditory organs.

Apart from the abovementioned physical effect on the auditory organs, this study looked into whether the presence of the INFOSOUND acoustic signal in any way places the human body under stress, regardless of the presence or absence of perception of “sound.”

Study Content and Results

Dates on which studies were performed November 7, 2011 (Adults); April 4, 2012 (Children)
Those surveyed 15 adults (in their 20s through their 50s), 18 children (from 1 to their teens)
Survey content Saliva was collected from each of those surveyed before and after transmitting an INFOSOUND acoustic signal. The anti-oxidation of the salivary component stress marker (cortisol) was then measured.
Survey results No stress response to the INFOSOUND acoustic signal was observed in either adults or children.

Note: There are plans to publish the results of this research after detailed analysis.

Having received the results of the survey, Yamaha will proceed with its aim to install INFOSOUND widely as an acoustic communication system that can be safely utilized. As smartphones rapidly become more widespread and more established in people’s lives, Yamaha will target the realization of more convenient and pleasant lifestyles in response to the growing need for combined online-offline services.


INFOSOUND is a Yamaha proprietary technology that transmits digital information modulated into sound signals. Using the very high frequency sound range enables the transmission of data at frequencies that are almost inaudible to the human ear. The INFOSOUND system sends short information codes (acoustic IDs) from speakers that are received by the microphones in mobile terminals. By using a mechanism that in conjunction with a server converts the acoustic IDs into URL information, users in the vicinity of the speaker are able to pick up coupons or access e-commerce sites and be offered services enabling them to do their shopping.

For further information, please contact

Yamaha Corporation

Members of the press and media

Corporate Communications Division, Public Relations Group

  • 2-17-11 Takanawa, Minato-ku, Tokyo 108-8568, Japan
  • Telephone: +81-3-5488-6601
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Members of the general public

INFOSOUND Project, yamaha+ Division

  • 2-17-11 Takanawa, Minato-ku, Tokyo 108-8568, Japan
  • Telephone: +81-3-5488-5070

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