Novel "Bird Sound Wave" - Practicing the "SF Prototyping" Method through Private-Sector Medical-Engineering Collaboration

This manuscript is a novel that practices the medical "I wish this existed" realization "Design Studio" that I, the author, have been working on since starting my business in March 2025. To get it on track, I practiced the Hoshi Shinichi Award method of "SF Prototyping" by referring to the book below which I encountered while submitting entries for six consecutive years. By the way, this is "SF Prototyping". Incidentally, this is a method of deriving innovative visions that utilize cutting-edge technology by sharing future images with others through SF (Science Fiction) works and using them as a springboard for discussion to leapfrog ideas. Although it is usually done by several people in a workshop, I finished it instead through a back-and-forth with generative AI as follows. I hope you enjoy it and that it serves as a reference for introducing the method.

Based on this, I participated in the "Street Medical Lab" starting in April 2025. I intend to backcast the worldview depicted here, and this time, conceive what kind of first step to design from reality? ...and make the final "innovative vision that utilizes cutting-edge technology" the first step toward an announcement in October. Now, please enjoy!

(Main Story)
"It's almost there. Let's do our best. Okay, hee, hee, hoo." "Hee, hee, hoo. Hee, hee, hoo."

Misaki, who was giving birth for the first time, was facing the greatest hardship of her life. She thought, a little too late, that she should have chosen the "painless delivery" that a friend who is a doctor overseas had mentioned... but in Japan in 2076, 40% of the population is elderly, so doctors (including Misaki) are extremely busy, and she had heard that doctors who are not anesthesiology specialists still perform general anesthesia, so she felt anxious and gave up on it. It can't be helped, I just have to do my best... Misaki, who had braced herself again, saw the face of her husband, Giichi, twisted in agony, reflected upside down in her eyes for some reason. She felt a sense of discomfort, but she had no time for that and had no choice but to continue the breathing method that had been used for over 100 years. Ugh! Does this really work? Lamaze, help me!! ...Perhaps hearing Misaki's inner cry, she suddenly felt relieved, and a few seconds later, a shrill cry roared out.

"It's born! Congratulations! It's a very healthy girl."

The midwife placed the baby on Misaki's chest, who was breathless. Hmm, she's kind of blue and slimy, not red at all! It's different from what I imagined... but, thank you. Thank you for being born healthy. Nice to meet you from now on!

After resting comfortably from the birth at dawn until the evening, we moved to a private room and welcomed our first night as a family of three. Since Giichi was rubbing his stomach as if in pain, Misaki was finally able to ask about the discomfort during the birth.

"Eh?! You don't remember?"
"Yeah, not at all."
"Misaki, you squeezed with all your might. Both of my sides, like a vise. I thought I was going to die, but since you were also risking your life, I decided to at least share the pain."
"Is that so. I intended to grab the head frame of the bed, but that's why I couldn't put strength into it well. Giichi, your stomach is squishy, after all."
"Shut up!"

At that moment, the daughter started crying, perhaps because she was hungry. Her name is Ayaka, written with the characters for "coloring" and "scent." I hope she likes it. I was thinking about that while breastfeeding, but maybe because it was my first time, it didn't go well. The milk wouldn't come out. The crying got louder and louder, and the tips started to hurt, and just when I felt like I was going to cry, Giichi suddenly whistled for me.

"Oh, this is 'Isn't She Lovely?'. Nice. I guess you associated it with the crying in the intro."
"Correct. This is a song from 100 years ago. It's soothing, isn't it? Don't panic, it will definitely come out."
"Thank you. That's a big help."

After I surrendered myself to the tone played by my husband for a while, Ayaka had calmed down before I knew it.

"She's asleep."
"Yeah, she's cute."
"Hey, I wonder why."
"What?"
"Ayaka... I wonder if she likes whistling."
"Well, she must have heard it even in the womb. I whistled and let her listen to it every day."
"I see. That's why she felt safe."

I first met Giichi at a whistling competition. I felt a sense of closeness because we were similar in that we both disliked competition. After that, I became a doctor, and thinking that it would be nice if everyone could be number one... I set out to develop technology to identify individuals by whistling. There, I reunited with Giichi, and we got together.

"I hope Ayaka will be able to whistle soon, too."
"Usually, parents hope for them to speak first, though."

Long before we were born, the principle of how whistling sounds was scientifically elucidated, so basically (unless there was a defect or disability in oral function), everyone became able to whistle. Therefore, there was no particular meaning in entering the competition; I just entered because everyone else was entering. But in the first place, even though the skeletal structure is different, and the length of the tongue and the alignment of the teeth are different for each person, I felt uncomfortable competing on the same playing field. Because, that means (even with the same flute) a recorder, a trumpet, and furthermore a trombone, a horn, a piccolo, etc., are all competing on the same level. That is absolutely strange! ...I felt that, and started investigating how much whistling differs from person to person. Then, surprisingly! I was able to scientifically prove that there is no one with the same soundprint, so then individual authentication is possible! And before I knew it, I was enshrined as the leading expert.

"Hey, do you think Ayaka can tell our whistles apart?"
"I think she can. Even bird chicks can tell their parents apart."

Giichi is an engineer, not a doctor. He studied electrical engineering but is also well-versed in biology; his specialty, if you had to name it, would be bioelectronics. It seems he was invited to our individual identification project because he had researched bird calls extensively as part of that work. He said it was because whistling originated from mimicking bird calls.

"That's it! Then, why don't we let her hear my and Misaki's whistles while we're at it?" "Sure, what should we whistle?"
"How about 'Stand by Me'? I think it's comforting."
"That's great. Then I'll whistle the main melody, and I'll leave the harmony to you, Giichi."

I wonder if it was just my imagination that the corners of Ayaka's mouth, who was listening while sleeping, lifted slightly.
　　　　　　　

Hin, kururururururururu!!!! Giichi's smart glasses rang frantically.

"Giichi! It's terrible!! The forest park is on fire!!!"

It was a ringtone for an emergency message from a junior colleague to Giichi, who had come to Kushiro for bird watching.

"According to the news, the habitat of the Japanese robin you've been observing is also in danger."

Without waiting to read the second message, Giichi put on his glasses and dashed out of the dormitory. There was still time before sunset! He didn't hesitate to launch the bird-shaped drone (a Narcissus flycatcher model) he had prepared for the next morning's observation. Japanese robins are territorial, but they coexist with Narcissus flycatchers. Since their habitats and prey are similar, and their breeding seasons and nesting sites are close, they likely have a relationship like "mom friends." That's why Giichi instantly thought he could use this to guide the Japanese robin to safety. As soon as he saw the yellow and black body soar up and head in the intended direction, Giichi waited for the live footage from the scene through his monitor.

The footage that arrived shortly after was horrific. With temperatures rising every year, the dryness was also progressing, and on top of that, there had been no rain during the rainy season that year, so the parched trees were being mercilessly swallowed by the raging fire. In the midst of that, he suddenly saw the long-awaited orange head. The built-in AI also identified it as a Japanese robin. The Narcissus flycatcher chirped, "Follow me!" and took flight. However, the screen showed the Japanese robin again. It wouldn't follow. During the exchange that repeated several times, Giichi heard the Japanese robin's cry. "Ka! Ka! Ka!" It was a signal to warn of danger, different from the gentle voice he usually heard. Its gaze was alternating between the Narcissus flycatcher and behind itself. When he zoomed in... it was a nest! There were chicks inside!!

"I see... then you can't follow me."
"That's right. There are three of them, so there's no way I can carry them."
"Humans say 'any port in a storm,' but can't they try hard and fly on their own?"
"I tried, but it doesn't look like it's possible. They were just about to fledge... it's frustrating."

The conversation in bird language between the AI installed in the Narcissus flycatcher and the Japanese robin flowed from Giichi's smart glasses as translated audio. The image of the chicks being swallowed by the flames was seared into Giichi's eyes, which were already a mess of tears.

"Hin, kururururururururu!!!!"

The parent bird's wailing, as if resenting the heavens, was painted over by flames of the same color as its lovely orange face.

It was triggered by a discarded cigarette butt. Giichi hated this old habit from the bottom of his heart, which for some reason never changed no matter how much the times moved on. No matter the reason, it was a full-blown fire. Isn't the act of discarding it arson? ...It's not a matter of manners! The feelings that had been festering inside him turned into hatred because of this incident. In 2075, the Japanese robin was classified as Critically Endangered (CR) on the Ministry of the Environment's Red List, meaning it was one step away from extinction. Even though it was once counted as one of the three great songbirds of Japan... and it happened because of such a foolish act!

Giichi's heart was a mess. His work, such as bird research and individual identification projects, which should have distracted him from his anger at such times, his relationship with his family, and even whistling, which had been such a part of his daily life, now only reminded him of sadness and regret, and were nothing but painful to him. Having lost his energy, he began to hear auditory hallucinations. A doctor diagnosed him with schizophrenia.

"Even if you try your best, it won't be rewarded. Because humans are creatures that pull each other down."
"You made something like individual identification for whistling. Society needs some leeway; it's too rigid."
"The Earth will eventually become uninhabitable. It's obviously the right answer to escape to space as soon as possible."

Hearing such voices, Giichi became increasingly lethargic and shut himself away. Seeing this, Misaki thought she would wait until his emotional wounds healed, but little Ayaka charged in, determined to cheer her father up!

"Hey Dad, you don't have to show your face, just listen. I learned the whistle you taught me before! Hin, kururururururururu!!!!"

The sound reached Giichi's heart, which had been submerged in darkness. It was a warble reminiscent of that Japanese robin. Come to think of it, he had taught Ayaka the technique of whistling called "warbling" before going to Kushiro. It is a playing method that changes the flow of air instantaneously by moving the tongue on and off the roof of the oral cavity, making the sound ripple clearly at high speed. A higher sound than Giichi's was emitted from little Ayaka's palate, as if the Japanese robin chick that had been swallowed by the flames had chirped for Giichi once again.

"Did... did Ayaka just whistle that?"
"That's right! Here, one more time. Hin, kururururururururu!!!!"

This time, the image of the parent robin appeared clearly in his mind, and it spoke to Giichi in an AI-like manner.

"Thank you for feeling my pain. We live within you, so do not worry."

And this was the last auditory hallucination Giichi ever heard.

Misaki was thinking about the miracle Ayaka had caused. How should she accept the reality that, using the sound waves of a whistle, she had casually cured her husband's mental illness, schizophrenia? Regardless, as a doctor, she felt the need to study it academically.

Music therapy already exists in the world. It is performed by experienced therapists who monitor a patient's reactions. Mental illnesses like schizophrenia are also targets for this. However, the way music is perceived varies from person to person, and for some, specific music can trigger strong emotions, calling up past traumas or sad memories. In such cases, there is a risk that it may conversely increase stress and anxiety. For this reason, this therapy has long been considered personal and artisanal, and is not widely used in clinical settings.

However, this time, her daughter, a complete novice, used it unintentionally and achieved results. If so, what if there were medical devices designed to avoid such clinical risks? She felt the possibility that music therapy could be liberated and further democratized.

Incidentally, Giichi said this when looking back on that moment.

"The reason I was able to come back is because Ayaka reproduced the image of the parent robin inside my brain. My mind broke because seeing the robin's tragic end caused my dissatisfaction with the irrationality of society to overflow. But thanks to Ayaka, I was able to find hope even in my grief, which I think is why I was able to repair my mind. Therefore, if we can make this process reproducible, I think it could become a medical device that the general public can use."

It is a difficult challenge, but it seems to have significant potential for the adult mental illnesses Giichi experienced, children's developmental disorders, slowing the progression of dementia, alleviating pain in terminal cancer, and organizing one's view of life and death. Above all, isn't this a theme appropriate for me to tackle, having enjoyed whistling as a family and even elevated it to individual authentication? ...Alright! Let's do it!! She vowed this while looking at her daughter's carefree smile.

First, she defined the medical device to be developed as follows.

① (Using whistle individual authentication) Activated by the whistle of someone the patient holds dear
② (Using those sound waves) Create an image in the patient's brain that fills their life with a sense of happiness
③ (Increasing the patient's stress and anxiety) Automatically and early avoidance of stimuli to trauma

① can be managed with whistle individual authentication, so let's focus on ② and ③. ③ seems doable if we develop a mechanism that uses a method called neurofeedback to measure brain waves in real-time and detect signs of trauma being stimulated early on. The problem, however, is ②: how to create an image in the patient's brain that fills their life with a sense of happiness... To start, let's conceive a prototype based on Giichi's example.

In Giichi's case, he visually recognized the robin through footage from a Narcissus flycatcher-type drone. That became a trauma, and also the key to unlocking the trauma. Ayaka's whistle happened to remind him of the robin, which allowed him to resolve the trauma, but whistling does not always act in that way. How do we explore stories that always act accurately on the issues that cause suffering for patients? ...It is quite a difficult problem.

While measuring many brain waves, she found a way to know the signs early when trauma was about to be stimulated. With this, she had a prospect for managing ③, but ② was beginning to run aground.

It was at that time that Giichi was diagnosed with an intractable disease.

"Don't be so serious. I don't have any particular subjective symptoms, and I can still work normally."
"But, you don't know the cause or the treatment... And since it's arteritis, it might spread throughout your whole body."
"That's true, but... it can't be helped. Sooner or later, humans always die someday."
"Daddy, are you going to die?"
"It's okay. I can't die until Ayaka grows up. Now come here. I'll whistle a lullaby for you."

Giichi acted brave, but as expected, before long, the inflammation spread from his skin to his major organs, and his condition rapidly deteriorated. Ayaka, overcome with grief, could no longer whistle her favorite lullaby herself. If she tried to whistle, she would be overwhelmed by sadness and couldn't do it. Since you can't whistle without raising the corners of your mouth, it was no wonder. And so, while being watched over by his family, Giichi passed away without any particularly effective treatment being administered. But his consciousness remained clear until the end, and he left these words for Misaki.

"Before, I said the reason I became mentally ill was because 'my dissatisfaction with the irrationality of society overflowed,' but lately I don't feel that's the case. I realized it when Ayaka couldn't whistle the lullaby anymore. I think the real reason was 'a sense of loss.' At that time, I lost sight of the true reason due to my anger at the robin's life being taken away irrationally. Deep down in my heart, I wanted to see the robin again. Ayaka made that happen with her whistle. So, even if I'm not here, I want you to make sure I am always inside Ayaka. I'm counting on you."

Inside Ayaka... I see! Maybe there just needs to be 'another person inside'.

Then, Misaki set the development goal as an "implantable nanomachine." When she thought, "How can Ayaka be able to play the lullaby that is her memory of Giichi again?" she realized, "It would be good if Giichi were inside Ayaka." In other words, what if Giichi layered his sound inside her body over the whistling played by someone important to Ayaka (me)? If the sound of a loved one and the sound that fills the sense of loss overlap, wouldn't the patient be able to revive the precious story themselves? Believing that the power to restore what was lost by oneself still remains, even if only slightly, in a wounded heart! Thus, the path for (2) was also set.

Having pivoted the development policy in that way, Misaki added two new challenges.

4. A power supply mechanism capable of operating for a long period inside the patient's body
5. Biocompatibility capable of evading the patient's immune system

However, Giichi had already mapped out the path for both of these to some extent while he was in his hospital bed before he passed away. For 4, as "a mechanism to convert the vibrational energy of the sound waves of whistling into electrical power." For 5, as "the possibility of reproducing within the human body the mechanism by which parasites evade the host's immune attacks." Misaki pushed forward with realizing these while keeping the whistling sound source left behind by Giichi echoing throughout the laboratory at all times.

The medical device developed in this way was named "Bird Sonic," and it passed pharmaceutical reviews in countries around the world and was launched on the market. It was valued as a partner for patients to satisfy senses that had been lost or were lacking from the beginning, and to coexist with their illnesses on their own (along with a sense of happiness).

In one country, an autistic child who lost his father early in life uses Bird Sonic to recall his father from his mother's whistling, and while being encouraged with, "You're okay. That's fine," he is expanding his interests day by day.

In another country, an elderly woman with dementia uses Bird Sonic to recall a friend from her high school choir days through her grandchild's whistling, and by singing dozens of songs she practiced back then from memory every day, she is stopping the progression of her illness.

In another country, a middle-aged single man suffering from an intractable disease uses Bird Sonic to recall a client through the whistling of a trusted colleague, and surrounded by voices saying things like, "Thank you so much for everything. I'm glad you were there," he is coming to terms with his view on life and death.

In another country, a woman with terminal cancer suffering from severe pain uses Bird Sonic to recall the nurse from when she gave birth through her son's whistling, and encouraged by, "It's painful, isn't it? But you'll see them soon," she is turning her pain into vitality.

And finally, the day came for Ayaka to use Bird Sonic as well. Since Ayaka, who is not ill, cannot use the implantable type which is a controlled medical device, Misaki had been proceeding in parallel with the development of an "earphone type" general medical device that can be operated even by people without specific qualifications, and she was finally able to launch it.

"With this, can I really meet Dad?" Ayaka asked, half-doubting.
"That's right. You just need to relax, close your eyes, and think of your father, Ayaka."
"It's kind of scary. I wonder if I can talk well."
"I see. You haven't talked for a very long time, have you? But it's okay. Your father is kind."
"Okay. I'll try. I'm going to go meet Dad."
"Yes, your father will be happy too. Tell Mom what you talked about later, okay?"
"Yeah!"

Misaki's whistling reaches Ayaka's ears through the earphones. Then, before long, Giichi's nostalgic whistling overlaps. The lullaby she couldn't play anymore, "Stand by Me"... her brain is filled with the wavelength of happiness. The sadness hasn't disappeared yet, but the sense of happiness is overwhelmingly superior. Ah, how pleasant it is.

Misaki, watching the monitor connected via the cloud, recognized signs of sadness in Ayaka's brain waves at the beginning, but it did not worsen beyond that and eventually disappeared... The safety device was operating normally, protecting Ayaka's heart.

"Dad."
"I'm home. I'm glad I could return to before you grew up. We promised, didn't we?"
"You returned? Really? Will we be together forever from now on?"
"Yes, that's right. I'm always in your heart, Ayaka, so if you want to see me, you can see me anytime."
"But I get sad, so I couldn't play this song anymore. Even though I love it."
"Is that so? But since we were able to meet like this, it's okay now. Come on, try playing it. You can play it."

Ayaka was still half-doubting, but the whistle she played tentatively, encouraged by her father, resonated unexpectedly strongly and firmly, and an octave harmony with Giichi was beautifully established. Actually, this was also with the help of the device, which was inserting a guide whistle in Ayaka's timbre while maintaining the sensation that she was playing it herself. Though that was only at the beginning, and it was ringing truly powerfully from halfway through.

"I played it! I played it!! Dad... thank you so much for everything. I've wanted to say that for a long time. But I thought if I said it, you would disappear, so when I held it in, you really disappeared. Ah, I'm glad I could say it. You know, I'm working hard on my science studies. Because I want to do a job like you when you were grown up, Dad. I've also memorized many bird names. I can even imitate their chirping with whistling."

And then, and then, Ayaka's story continued as if a dam had broken. And by the time the tears she had cried halfway through had completely dried... "Okay, see you again," she said, and finally opened her eyes.

"Dad, how was it?"
"Yeah, he was doing well. I talked so much that I forgot. Or rather, I feel like I was the one doing most of the talking. Oh! But he said one very important thing."
"Eh? What, what?"
"That I'll have a little brother soon."

Misaki lost her words. Why would Giichi say that? ...No, no, this shouldn't be the person himself, but an image created by Ayaka... Ah, I see, this girl had been feeling it. The existence of the little brother in her womb. But how should I say it... even though the little brother's eyes have lost their light.

"I knew it. I don't know if it's a little brother, but I knew there was something inside you, Mom. Is it really a little brother?"
"Yes, that's right. But I don't really know..."
"Yay!!! I've wanted a little brother for a long time. Thank you, God!"
"But you know, Ayaka. Your little brother cannot see. I wonder if he will grow up healthy."
"It's okay. He has good ears instead. He moves a lot at my voice."
"You, you even know things like that?"
"I know. I can't explain it well... but I feel it. Since we are siblings, aren't we connected? Besides, Dad did his best at the end, didn't he? I'm just happy that he's going to be born. Eh? Mom, what's wrong? I don't like it when you cry."

Hey Giichi, I'm so happy. We kept our promise to each other, didn't we? And one more thing, I will definitely give birth to our younger brother in good health. And I will give him the name you left behind. So that he can live a wonderful life with his whistling. And someday, he will teach me. Just how rich it is to live in a world of only sound.

Named "Haku".

<<End>>