Cutting-edge NTT communication technology that will change the world



Connecting technologies, connecting with technologies. Turning children’s voices into a bridge of hope.

The Torch Relay is a symbol of passing hope onto the future, transcending time and place. However, even for elementary school children, for whom this will be the first time watching the Torch Relay, cheering from the roadside has been prohibited. “Is there any way we can let them experience the joy of cheering, if only a little?” After trial and error we ended up with the good old paper cup. We employed a microphone using a paper cup that invites one to use it over and over again, we collected children’s voices and played them on speakers while displaying them on an electronic signboard using NTT’s voice recognition technology. It is our wish for the children that by hearing and seeing their voices through “sound” communication technology, they will get a glimpse of its potential for the Torch Relay and for science.


Loud cheering made possible despite the COVID-19 pandemic Hope in the name of technology,
embodied by a paper cup

Hope in the name of technology, embodied by a paper cup

The Torch Relay is the symbol of the Olympic games. It was ignited in Olympia, Greece, and then was brought to Japan and carried around the country. As a communication company with the mission to connect people and objects, NTT has supported the Tokyo 2020 Olympic Torch Relay, identifying with the mission of relaying the Olympic Torch.

Known by its researchers and local residents by the nickname “Yokosuka Tsuken,” NTT’s Yokosuka research & development center is a symbol of NTT’s research and development to preserve hope for the future in the name of technology. For the Tokyo 2020 Olympic Torch Relay, the center had been included in the Torch Relay route.
However, having the Torch Relay on public roads was to be banned later due to COVID-19. Sadly, the Olympic Torch would no longer show up at the center, and the elementary school children looking forward to cheering the Torch Relay would no longer able to see the real Olympic Torch. Young researchers of NTT’s research lab asked themselves, “Is there anything we can do to deliver their cheering despite COVID-19, using communication technology?” and after much trial and error, proposed voice recognition technology featuring a microphone made with a paper cup, and successfully delivered children’s cheering, connecting people with hope.

Young NTT employees in charge of the project
Young NTT employees in charge of the project

“Instead of just clapping, we wanted to safely deliver everyone’s cheering somehow. All of us in the development team had countless discussions and eventually came up with a new way of cheering, combining paper cup microphones with the sound recognition technology that NTT has spent years working on.”

The paper cup microphone itself is a simple tool made with just a paper cup, a magnet and an enamel cable, but when connected to a smartphone, it is able to pick up even tiny cheering voices. Cheering collected from multiple paper cup microphones is then reflected with the most advanced voice recognition technology as an image displayed on a monitor, heightening the sense of unity at the event. As people would cover their mouths with the paper cup microphones, it would also prevent droplet infections.

Even though the paper cup microphone’s mechanism looks rather simple, development of a matching voice recognition engine was quite a challenge.

“Unlike regular microphones, picking high-frequency sounds with paper cup microphones is rather difficult. Our conventional sound recognition engine was unable to get the right results. So, we gathered test data with paper cup microphones first, analyzing the data to improve our sound recognition engine, eventually creating a matching sound recognition engine for this project’s paper cup microphones.”

Children crafted all of the paper cup microphones with their own hands, after a lecture from NTT employees. Thanks to this effort, they were able to experience that technology could address the hurdle of not being able to talk loudly during the COVID-19 pandemic, feel closer to technology and understand the joy of making something.

“There were three things we were aiming for with this project. First, we wanted children to make the paper cup microphones themselves and enjoy doing that until the day of the event. Second, instead of us just giving them something to work on, NTT and the children would work together to create and have children fully enjoy the event. Third, to use our voice recognition technology to visualize the cheering collected from the paper cup microphones, visualizing the cheering on a display and playing it on speakers at the venue for people waiting to hear it, so that the children would know their voices reached others.”

Cheering with a smartphone-connected paper cup microphone
Cheering with a smartphone-connected paper cup microphone

“Seeing the children enjoying cheering with the paper cup microphones made us so happy that we took on this project. It gave them the chance to know that the cheering collected through the paper cup microphones they made could take shape like that. I hope this has given them an opportunity to take interest in science, if only a little.”


Sound-based communication technology accelerates excitement and sends the heart racing.

Communication means exchanging signs. NTT has been researching and developing not only networks but how signs (= sound) can be collected and transmitted. Lately we have seen voice recognition technology rapidly spreading in the public, thanks to the emergence of “voice assistants” that give us the information we need when we talk to our smartphone. This time NTT organized an event to use such voice recognition technology to have as many children as possible experience the excitement of the Torch Relay that had been scheduled to pass through NTT’s Yokosuka research and development center.

Flow of the event
1. The elementary school children are to create paper cup microphones in advance themselves, under a lecture by NTT employees.
2. On the day of the Torch Relay, they connect the paper cup microphones to smartphones to collect their cheering.
3. The cheering is played on speakers and reflected on a monitor as an image.
The children’s cheering was delivered through the speakers and displayed on a monitor with the voice recognition technology, heightening the sense of unity for the event.
The children’s cheering was delivered through the speakers and displayed on a monitor with the voice recognition technology, heightening the sense of unity for the event.

Even though COVID-19 prevented direct cheering, NTT’s voice recognition technology combined with a familiar object that is a paper cup enabled children to have a glimpse of sound-based communication technology. Utilizing communication technologies, NTT will continue research and development to pass on hope to the children, the bearers of the next generation, and to our society.

Tokyo2020 Olympic TORCH RELAY



Leading telecommunications technology

NTT Tokyo 2020 Olympic Torchbearer Secretariat

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