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The Experience of Sound: An Interview with Ron Miles

Professor Ron Miles, inventor of Soundskrit's microphone, discusses his research and why sound is so important.

The Experience of Sound - An Interview with Professor Ron Miles

By Brad Diamond
2023-06-26

Our World of Audio

Ron Miles, Distinguished Professor of Mechanical Engineering

Sound is universal. It is the wind whistling through trees, the tapping of my fingers on this keyboard, and the ding of my phone when my friend texts me. Any human experience can be relayed or enhanced through sound. Sound can connote a sense of joy, pain, sorrow, or relief.

As Distinguished Professor Ron Miles puts it, hearing is connection. When I say “I hear you”, I am doing more than acknowledging sensory input; I am sharing that I understand you. Sound is fundamental to the human experience, serving as connector and communicator for many people.

Sound, used as both communicator and creator of a collective memory, is the most fundamental reason for humanity developing civilization. The first stories were not written down but told within communities. They served to entertain and to forewarn of danger, but also managed to bring people together in shared experience.

The urging of music spurs emotion, a few notes on a piano bringing back feelings from a decades old wedding. Tears are wept after an excellent soliloquy. The human life is an experience of sound.

We at Soundskrit want people to hear our story, to give a better understanding of our company. That story begins with Professor Ron Miles, the inventor of our technology. We sat down with Professor Miles, to relay his whole story.

A Sound Life

Miles was curious about acoustics ever since a young age. Throughout pursuing his electrical engineering degree at Berkeley, that curiosity did not falter. After graduating, Miles received a job with Boeing, working in their acoustics department.

At Boeing, Miles worked at reducing the noise in airplanes. Because airplanes travel so quickly, there are pressure fluctuations on the outer structure of the airplane. This creates loud noise that would be too uncomfortable for passengers.

The solution for this problem became the subject of Miles’s Master’s. In his research, Miles found that vibration dampers reduced noise and weighed less than existing solutions. The aerospace industry is especially sensitive to weight due to the high cost of fuel and Miles’s research showed how dampers could reduce fuel consumption without sacrificing passenger comfort.

After spending some time at Berkeley as a postdoc, Miles moved to Binghamton University and took a position teaching there. His wife worked as a postdoc in a lab studying insects at Cornell University. It was through her research that Professor Miles was first introduced to the hearing systems of insects: specifically, that of the Ormia fly.

Nature Inspired Research

Ormia Fly
Ormia Fly

The Ormia fly has two eardrums that are coupled together in a unique way which enables the fly to determine the orientation of a sound source. The discovery of this approach to directional hearing by Miles and his collaborators became the basis of the first directional microphone Miles worked on, work primarily funded by the US National Institutes of Health for the purpose of creating advances in microphones that are used in hearing aids. The focus has been to greatly benefit the hearing impaired and bring audio experiences into their lives.

For the past 30 years, Ron Miles has studied these and other hearing systems, using the backbone of Mother Nature’s evolution to create better products for humanity. Around 70 patents were issued from his research conducted on the Ormia fly’s hearing system. After sorting out how the coupled eardrums or the Ormia fly enable directional hearing, Miles became interested in directional hearing of other insects, particularly insects that don’t have eardrums at all; most insects that can hear sound use thin hairs to detect the movement of air in a sound field rather than the sound pressure which is what causes eardrums to respond. The study of the sound-induced motion of hairs led to exploring how sound moves other thin structures and eventually led to the study of the acoustic response of thin spider silk.

This acoustic response of spider silk was first discovered by Miles’s grad student, Dr. Jian Zhou. On a walk-through Binghamton’s nature preserve. Jian observed the spider web flowing in the wind and supposed that the silk might respond well to the minute air motion in a sound field. Placing it in their anechoic chamber, Miles and Zhou found that the spider silk sensing sound as well as any microphone, therefore proving that a very fine fiber can be used to measure sound. In a subsequent study, another graduate student of Miles, Dr. Junpeng Lai showed that a spider sitting on its web can actually hear sound because of the sound-induced web motion; spiders might be using their webs as an extended ear, or as a sort of external microphone.

The Physics of Sound

When sound is taken at very small scales, the air that sound propagates in can be treated as a viscous fluid. This was shown by George G. Stokes in 1851, as Professor Ron Miles discusses in the following clip:

Very fine fibers, like spider silk, can take advantage of this viscous drag to sense sound. This produces an extremely directional method of sensing sound since it is responding to the directional motion of air particles.

Furthermore, the spider can use the web to sense sound. Some spiders can sense sound using tiny hairs on their body, but Miles and his team found that when the spider was placed on its web in an anechoic chamber, it would respond to sounds played in a certain direction. The spider was able to use its web to directionally sense sound, showing that for some spiders a web can become an external microphone.

Soundskrit took inspiration from the spider’s design and used Miles’s research to develop our directional MEMS microphone. Our microphone utilizes millions of years of evolution in its design, creating a high-performance MEMS microphone like no other. All we had to do was listen to the world around us.

Connecting the World

With this new design, Soundskrit’s MEMS microphones offer high performance, directional audio capture for any consumer electronics. We hope to greatly benefit the world around us, by contributing to the consumer electronics devices of the future. By taking inspiration from nature, we make the microphones of tomorrow, as their inherent directionality produces the best audio quality for consumers.

For Ron Miles, the real goal was always to learn more about the world around us, specifically the way acoustics works. This is a dream that has extended throughout his whole life. And even still, there are questions left unanswered.

The Orb Weaving spider, photographed by Junpeng Lai, which senses air using its hairs and its web.

 

How can the Ormia fly have directional hearing while it is flying? By all rights, the sound of its wings should drown out any other sound, yet it is able to hear while flying. So far, Professor Miles did not have the answer, but he hoped that someday soon the world would learn. For Miles, that is part of the beauty of his work. Every question yields an answer, and every answer yields more questions.

Like all great work, this wasn’t accomplished alone. Professor Miles was joined by Professor Ron Hoy, a neurobiologist from Cornell, Daniel Robier, a collaborator on the Ormia fly, and Jian Zhou, Miles’s grad student who worked on the spider silk measurement. Through these researcher’s effort, great strides were made into understanding the world around us.

Understanding through Audio

As we research deeper into how the world around us works, we move beyond sensing the world into understanding the world. This understanding starts with sound.

For Ron Miles, audio has been a way to connect with the world. Sound holds answers for why the way our world works, answers he has searched for. More than just a job, sound is a passion for him.

Like Ron Miles, Soundskrit believes in the power of sound. For us, audio is more than just a part of our business strategy. It is more than a qualification we are trying to achieve.

Sound is life. We believe in bringing the most amazing things happening in the audio world to the world’s attention. And for us, that starts with Professor Ron Miles.

Credit to Binghamton University for the photos provided. Read more about Professor Ron Miles here!

Want to learn more about Soundskrit's microphones? Check out our digital microphone here!