Noise Notifier: A Persistent Reminder to Keep It Down

This project began as a simple re-entry into coding and physical computing after a long break. With little prior experience working with hardware, the goal was to build something small, practical, and immediately useful. The result was the Noise Notifier—a device designed to detect excessive noise levels and respond in a way that makes people aware of how loud they are, without relying on constant human reminders.

The motivation behind the project was personal and relatable. After sharing living space with my sister for years, it became clear that she genuinely did not realize how loud she could be. Verbal reminders were easy to dismiss, but the idea of a neutral, objective device reacting to noise felt harder to ignore. The concept was simple: if a tool reacts, maybe the problem is real.

The core idea was to build a system that continuously monitors ambient sound levels and triggers an alert when the noise crosses a predefined threshold. When the environment becomes quiet again, the alert stops. The intention wasn’t to punish, but to create awareness—something that quietly encourages self-regulation over time.

To begin, I tested a basic sound sensor by connecting it to an LED. When the detected noise exceeded a certain level, the LED would turn on. This step was crucial for understanding how the sensor behaved and how sensitive it could be. After several adjustments to the sensitivity potentiometer, I was able to reach a configuration where louder sounds reliably triggered the LED. Seeing this work for the first time was extremely motivating and confirmed that the basic concept was viable.

Encouraged by this progress, I replaced the LED with a buzzer to make the feedback more direct and harder to ignore. This is where the main limitation of the project became clear. The sensor performed well with sharp, close-range sounds, but struggled significantly with sustained noise or voices coming from across the room. For a device meant to monitor general room noise, this limitation was critical. The buzzer either failed to activate when it should have, or only responded to very specific sound patterns that didn’t reflect real-world use.

After testing multiple configurations and placements, it became clear that the sound sensor itself was the bottleneck. While it worked for learning and experimentation, it simply wasn’t suited for detecting consistent ambient noise at a distance. This limitation meant the device couldn’t fully meet its original goal in its current form.

Despite this, the project was far from a failure. It turned out to be an excellent learning experience and a strong introduction to physical computing. It showed how accessible hardware projects can be, even for beginners, and how quickly an idea can turn into something tangible. It also highlighted the importance of choosing the right components for a specific problem, rather than assuming all sensors behave the same.

The Noise Notifier remains a concept I genuinely like and plan to revisit. With a higher-quality microphone module or a sound level sensor designed for ambient measurement, the idea could be refined into something genuinely effective. More importantly, the project taught valuable lessons about research, documentation, troubleshooting, and the importance of taking notes throughout the build process.

Most of all, it sparked excitement to keep exploring physical computing—turning everyday annoyances into opportunities to learn, experiment, and build something real.