"Is all noise bad?"
Yuki suddenly asked.
Aoi looked up with interest. "Interesting question. Why do you think so?"
"Just now, Professor S. said 'moderate noise is beneficial'."
Riku was doodling on the whiteboard. "Noise is a nuisance, right? It hides signals."
"Generally yes," Aoi answered. "But information theory isn't omnipotent. Depending on the situation, noise helps."
"What situation?"
Professor S. entered the club room. "Good timing. Talking about noise?"
"Yes. About cases where noise is helpful."
The professor nodded. "There are several examples. First, dithering."
"Dithering?" Yuki opened her notebook.
"An image processing technique. Intentionally add minute noise to make gradation look smooth."
Aoi supplemented. "Human eyes average and perceive random patterns. So noise improves visual precision."
"Noise increases precision?" Riku was surprised.
"Paradoxical, but true," the professor said. "This is called stochastic resonance."
"Stochastic resonance..." Yuki wrote it down.
"A phenomenon where weak signals become detectable with noise's help."
Aoi drew a diagram. "When signal cannot exceed threshold, noise pushes it."
"But noise is random, right?" Riku questioned.
"Yes. But with repeated observations, signal components accumulate while noise averages out."
"Statistical effect," Yuki understood.
The professor continued. "In machine learning too, noise is important."
"Why?"
"Prevents overfitting. Adding noise to training data generalizes the model."
Aoi gave an example. "Learning from perfect data makes you weak to real-world noise. So, intentionally inject noise."
"Like a vaccine," Riku said. "Build immunity with weak virus."
"Good metaphor," the professor acknowledged. "Noise injection makes systems robust."
Yuki asked. "But how much noise is appropriate?"
"That's difficult," Aoi answered. "Too little has no effect. Too much destroys signal."
"Existence of optimal noise amount."
"Yes. Finding it is engineering skill."
Riku offered another perspective. "Is noise also necessary in human conversation?"
The professor smiled. "Sharp. Actually, human communication needs redundancy."
"Redundancy and noise are different?"
"Subtly different. Redundancy is planned duplication. Noise is unplanned fluctuation."
Aoi explained. "But both make information transmission robust."
"For example?" Yuki asked.
"Fillers like 'um' and 'uh'. Zero information content, but create conversation rhythm."
"True," Riku agreed. "Perfectly organized speech is mechanical and cold."
"Noise creates human-likeness."
The professor supplemented. "For creativity too, noise is indispensable."
"Creativity?"
"Completely deterministic systems don't create new things. Randomness enables exploration."
Yuki's eyes sparkled. "Evolution also progresses with noise called mutation."
"Exactly," the professor nodded. "Noise makes systems explore and opens new possibilities."
Aoi summarized. "Noise is neither enemy nor ally. Depends on usage."
"Moderate noise enriches systems."
Riku laughed. "Is my idle talk also beneficial as noise?"
"Probably," Aoi laughed back. "But in moderation."
Yuki wrote in her notebook. "How to make noise your ally:
- Find appropriate amount
- Use statistically
- Increase robustness
- Promote creativity"
The professor said as he left, "Perfect silence is actually poor. Moderate noise enriches the world."
Pleasant chat returned to the club room. That too might be beneficial noise.