"Riku, you're like a noise generator."
Yuki said this half-jokingly. After-school club room, Riku being noisy as usual.
"That's harsh! I'm transmitting important information too," Riku protested.
Aoi said with a laugh. "But your signal-to-noise ratio is low."
"S/N ratio?"
"Signal-to-Noise Ratio. The ratio of signal strength to noise strength."
Riku tilted his head. "My talk is noise?"
"Not all noise," Aoi explained. "But important information and unimportant information are mixed."
"For example?"
Yuki gave an example. "Yesterday, Riku explained how to solve a math problem. But in the middle, you interjected 'By the way, what did you eat for lunch?'"
"That's natural conversation flow though."
"But for the listener, it's noise," Aoi gently pointed out.
Riku pondered. "So how can I increase my S/N ratio?"
"Strengthen the signal or reduce noise."
"Specifically?"
Aoi headed to the whiteboard. "In communication, there are several methods."
"First, clearly declare the topic. If you say 'I'm going to talk about math now,' the receiver can prepare their filter."
"Filter?"
"The listener can more easily select relevant information. The brain's noise filter."
Yuki supplemented. "Also, reduce redundancy. Don't say the same thing repeatedly."
"But wasn't redundancy necessary for error correction?" Riku sharply pointed out.
"Good observation," Aoi was impressed. "Balance is important. Moderate redundancy is good, but excess becomes noise."
"That's difficult."
"So adjust while watching the other person's understanding level. Repeat if they don't seem to get it. Move on if they understand."
Riku was listening seriously. An unusual sight.
"Another thing, share context," Aoi continued. "With common background knowledge, you can convey more with less information."
"Information density increases," Yuki said.
"Yes. Conversely, without context, you have to explain everything. That can sound noisy."
Riku wrote in his notebook. "So I'm not conscious of my audience?"
"Not that you're not conscious. But your own interests tend to take precedence."
"I see..."
Yuki said gently. "But Riku's noise can be fun sometimes too."
"Huh?"
"Your unpredictable remarks make conversations interesting. If it were completely noise-free, it might be boring."
Aoi nodded. "Indeed. Randomness is also a source of creativity."
"So my noise is a necessary evil?" Riku asked jokingly.
"Maybe a necessary good," Yuki laughed.
Aoi summarized. "Communication is optimization of S/N ratio. Too high becomes mechanical, too low causes confusion."
"Moderate noise creates humanness."
Riku stood up. "Alright, I'll consciously adjust my noise from now on!"
"That's a good goal," Aoi acknowledged.
"But don't eliminate noise completely," Yuki added. "Your Riku-ness would disappear."
Riku laughed as if embarrassed. "Balance, huh."
Outside the window, city noise could be heard. Car sounds, people's voices, bird chirping. They mix together to create the signal called daily life.
"Everyday life with high noise levels isn't so bad," Riku murmured.
"Finding meaning from that noise is information theory," Aoi said quietly.
Yuki smiled. "Our daily life is also a continuous signal processing."
The three nodded to each other. Rich daily life where noise and signal coexist. That might be what human life is.