Syrinx: This prototype ‘artificial larynx’ aims to give cancer survivors back their own voice

“I had esophageal neck cancer and lost my voice about 10 years ago and made a smooth recovery,” Ogitsu said. “But I had a recurrence almost two years ago and ended up being unable to speak without a device.”

Ogitsu underwent a laryngectomy, a surgical procedure in which all or part of the larynx – also known as the voice box – is removed. This procedure can be part of the treatment for laryngeal cancers, which affect more than 184,000 people worldwide each year, according to the World Health Organization.

These days, Ogitsu volunteers at Ginreikai, a laryngectomy support group in Tokyo, Japan, where he helps people learn to speak again using a voice device called the electrolarynx.

The traditional electrolarynx is a razor-sized device that is held against the neck and creates vibrations which in turn transmit sound through the movement of the tongue and lips.

But there haven’t been many improvements in sound quality and functionality since its invention over 100 years ago.
Masaki Takeuchi began designing the artificial larynx prototype, Syrinx, in 2019.

After talking with Ginreikai members about their difficulties, Masaki Takeuchi, a young engineer, decided to create something new and better.

In 2019, Takeuchi and a group of graduate students from the University of Tokyo developed Syrinx – a wearable, hands-free, machine-learning electrolarynx.

“Patients said they wanted to speak in public without any inconvenience or embarrassment,” Takeuchi told CNN. “This project was started to develop a good device to do that.”

Speech restoration options

For patients who lose their ability to speak after a laryngectomy, there are currently three speech rehabilitation options, according to Yvonne Knapp, speech pathologist at Weill Cornell Medicine in New York.

There is the traditional electrolarynx, which is currently used by Ogitsu. Another option is esophageal speech, Knapp says — a learned technique where air is swallowed into the esophagus and pushed back, creating vibrations on the throat that are then transformed into speech. It’s the oldest and most difficult of the voice restoration options, Knapp says, adding that less than 40% of patients can achieve it, and only 5% can do it well.

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The third form of speech rehabilitation, and the most popular according to Knapp, is the tracheoesophageal puncture, or PET scan. This surgery creates a small hole between your trachea and esophagus, where a prosthesis can be inserted to allow air from your lungs to vibrate the muscles in your throat to create speech.

Knapp, who has worked with laryngectomees for 26 years, says PET is much easier than esophageal speech and “is far superior in sound quality to electrolarynx.”

However, not all patients are able to get the PET procedure. And for those who can’t, external voice aids like the electrolarynx may present themselves as a good option for voice restoration. But the devices can produce monotonous, unnatural speech, and they can be difficult to use. Ogitsu also pointed out that he couldn’t use both hands freely with the traditional electrolarynx.

“The problem with the electrolarynx is that it’s very robotic,” says Knapp. “People don’t like it and they tend to put it in a drawer and never use it again.”

A more human electrolarynx

The main difference between the traditional electrolarynx and the Syrinx is how Takeuchi’s device creates sound.

“Conventional devices use pulsed waves, which can produce loud sound, but are far from human voice – more robotic and mechanical. So we took human recordings and processed them to create sounds closer to human voice. ‘a human voice,’ he said.

Additionally, a traditional electrolarynx has one transducer (an electromechanical vibrator that creates sound) while Syrinx has two – which generate a wider range of sound wave frequencies that the user can translate into speech through articulation. tongue and lips.

The Syrinx prototype has two transducers, which Takeuchi says allow for greater vocal pitch.

These two components combined can create a more natural-sounding voice, according to Takeuchi, but the device is still in the early prototype stage and the technology is constantly evolving.

“We only used (artificial intelligence) at the beginning, but now we don’t,” he said. “In the near future, we would like to introduce AI again to create sounds that are much closer to human voices.”

Takeuchi says the device can also incorporate a user’s old voice recordings, if they have any, to sound even more like their old voice – an important option for many patients.

Our voices are so intertwined with our identity, Knapp said.

“[Say someone calls] you and you don’t know who’s on the other end of the line, but this person says a syllable and you know who it is, and you know what they feel from a syllable”, a- she said, “That’s what a voice can convey, and it’s super powerful… When you steal that from them, it’s really, really hard.”

Express strong opinions

As part of the research and development of the device, Syrinx is continually tested by Ginreikai members.

Takashi Sugiyama, a 75-year-old pharyngeal cancer survivor, tested the devices about seven times. He said it still seems too mechanical but progress has been made over time. In his latest tests, he claims the sound is clearer and very easy and comfortable to wear.

Takashi Sugiyama, a 75-year-old pharyngeal cancer survivor, periodically tests the Syrinx prototype.

Ogitsu, who tests the device about once a month, says he wishes Syrinx’s straps were more elastic to fit better around his throat.

Although Knapp hasn’t seen the device used in person, she said it may have a bit more depth than a traditional electrolarynx, but it doesn’t sound too different from what’s currently on the market. Marlet.

But she added that the hands-free feature could be a game-changer for some patients.

The device is already gaining recognition in Asia, with Syrinx winning the 2021 Grand Prix at the Japan Healthcare Business Contest and the Microsoft Imagine Cup Asia Regional in 2020. Eventually, Takeuchi would like to expand its product globally and have US testers .
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For now, he says he is working to reflect feedback he receives from Ginreikai in future iterations of the device.

“I’m so happy to hear that people were amazed by this device and said, ‘I can’t wait to talk with this device,’ and ‘I hope it’s released soon,'” Takeuchi said, adding that he hopes to pass the strict selection criteria required for clinical trials and bring Syrinx to market within the next decade.

Ogitsu agrees that he would like to see this device fully developed and available as soon as possible.

“I strongly feel how grateful I am to use my own voice for communication and how important communication is for human beings and society,” he said. “I believe we can lead a more normal social life by using both hands while speaking like a healthy person.”

CNN’s Junko Ogura contributed to this report.