Technology

Industry-Leading*
Noise-Canceling Technology

Delivering the Best Music
Experience to Customers

  • Kohei Asada

    R&D Center,
    Sony Corporation

  • Shinpei Tsuchiya

    R&D Center,
    Sony Corporation

  • Ichiro Nakajima

    Sony
    Home Entertainment &
    Sound Products Inc.

Once Halted Development Bears Fruit After Over 10 Years

These days, Sony has built an unshakeable position for itself in the noise-canceling (NC) field. However, the journey there was long and full of pitfalls. Sony released the world’s first analog noise-canceling headphones for consumer use in 1995. At the facility now known as the R&D Center, it had been developing digital NC technology at the same time, but encountered a lot of a problems with the performance and power consumption of the digital signal processor (DSP), and finally decided to interrupt the project. Kohei Asada, R&D Center, Sony Corporation, who has been working in development since 1993 reflects, “I knew that in the future, digital NC would be able to provide much better sound quality of headphones, so I continued to hope and believe that one day, we’d try again.”

In 2006, Asada was given another chance. DSP and driver unit’s performance, as well as acoustics technology, had improved considerably, and so they restarted their digital NC project. “I’d had experience with digital AV receiver technology, and so I thought that it was definitely possible this time. I really wanted to solve the NC performance and sound quality issues through digital technology.”

Asada finally achieved his dream of providing high quality sound even in noisy environments with the world’s first digital NC headphones, the MDR-NC500D (bottom), released in 2008. Digital NC technology has been widely used in headphones ever since.

World’s first digital NC headphones,
the MDR-NC500D

Achieving Differentiation Through
the Development of the Trinity

We asked Asada to tell us a little more about how NC works. “The technology basically involves removing ambient sound by measuring it and mixing the antiphase into the audio signal,” he explains. “The most important thing is to send a signal that will eliminate any noise at the eardrum’s position that leaks in through gaps in the housing. Ambient sounds don’t just stop, so continuous real-time processing is also absolutely essential. Complicated processing is not possible with analog systems, but digital technology allows us to send a very precise signal to remove all unwanted noise.”

General principle of noise cancellation

Sound quality has also considerably improved relative to analog NC headphones. Ichiro Nakajima, Sony Home Entertainment & Sound Products Inc. tells us that “the basic premise for headphones is to produce high quality sound. With digital NC, we were able to achieve incredibly high sound quality that simply wasn’t possible with analogue NC.”

During this period while digital NC was starting to take off, the relationships between the R&D Center and the Product Design Division were strengthened, reflects Shinpei Tsuchiya, R&D Center, Sony Corporation. “In order to adequately demonstrate the abilities of NC technology, it’s also important to make special headphones. The Product Design Division looked after the driver unit, the construction of the housing, and the electrical circuits. We were in charge of the DSP and the software, bouncing ideas off each other while continuing our fine tuning.”

Nakajima says that Sony's strengths lie in this trinity of acoustics, hardware and software. “Sony develops everything inhouse, from the driver unit to the DSP. As a result, we can differentiate ourselves from other companies. Of course, design is also important for headphones, but depending on the design, it may negatively impact the NC performance. From the very beginning of development, we made it clear this was one area where we would absolutely not compromise. Following that, we set up a design flow and have been able to achieve the best NC performance possible.”

The team is always aiming to improve NC technology, setting up working groups within the company and sharing information between divisions. “We hold talks with various divisions, and we almost play the role of consultants. I really came to understand how important NC technology is in so many different areas,” says Tsuchiya.

Reaching New Levels of NC Performance
with the WH-1000XM3 Wireless NC Headphones

With the new WH-1000XM3 headphones, they have achieved industry-leading* NC performance. Asada and Tsuchiya, who work together on NC technology, are brimming with confidence. “We produced a new NC algorithm, and together with the Product Design Division, also developed a new LSI, called the HD Noise Canceling Processor QN1. The NC processing is even better than the previous model, and the performance is like never before.”

The WH-1000XM3 is equipped with the “Personal NC Optimizer” developed by Tsuchiya which helps to adjust the NC performance to match the user. After putting on the headphones, long-pressing the NC button plays a test signal tone which analyzes the sound characteristics caused by head size, glasses, and hair, then optimizes the NC performance for that user. Asada tells us more. “When we first developed our digital NC headphones, we really wanted to make ‘thinking’ headphones. I think we’re steadily getting closer.”

Being recognized for its high performance, the WH-1000XM3 has been employed for use in all international first-class seats of All Nippon Airways (ANA) from March 15, 2020.
https://www.sony.jp/CorporateCruise/Press/202002/20-0225/

32-bit highprecision audio signal processing,
Low distortion and high signal-to-noise ratio allow for highly accurate active NC
and exceptional sound quality, the WH-1000XM3

The Unconventional Way May
Become the Right Way 10 Years Later

Tsuchiya tells us a bit more about the development process of NC technology. “Originally, audio was all about trying to faithfully reproduce the original sound. NC headphones add extra sounds to the original signal, and there are some people who may see this as a taboo, but we do share the same desire to enable people to enjoy high sound quality.” Asada adds, “If it’s good, technology seen as the unconventional way now may be accepted as the right way 10 years later. At the R&D Center, I’d like to continue producing excellent technology, even if it’s divisive.”

“In development, it’s very important to have a lot of interests and have an overhead view of things,” continues Asada. “If you are interested in a lot of different areas and find a way to bring them all together, a new technology might be born. Digital NC technology took about 15 years to make it to the world. While retaining an open mind, it’s important to be persistent and to never give up trying to achieve the technology you want to make.”

*As of December 1, 2019, according to research by Sony Corporation, measured using JEITA-compliant guidelines. In headband style of wireless noise canceling headphones market.

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