Squack, sound sponge

What it does

This tactile object converts touch into auditory feedback, offering children an emotionally resonant and playful new sensory experience. Through material transformation and sound expression, it inspires curiosity, imagination, and joy.

Your inspiration

The idea began with my personal experience—recalling how strange and pleasant it felt to squeeze a sponge. Though a common object, its soft, absorbent texture carries a unique, intuitive tactility. I wondered: what if this familiar material could absorb sound instead of water? Exploring this, I studied works like Noisy Jelly, Sound of Light, and Singing Plant, which transform physical data into sound. But I wanted something more emotional—where touch triggers memory, not just reaction. I was inspired to reinterpret the sponge as a tool that converts tactile gestures into audio experiences, flipping senses from touch to sound.

How it works

Squack operates in two distinct stages using a sponge embedded with a bending sensor and an ESP32 microcontroller. 1. Recording Mode When the user draws on the sponge’s surface, the motion is detected and the device enters recording mode. A parrot-like squawk sound plays to signal the change, providing immediate auditory feedback that strengthens user interaction and mode awareness. The device then records a short voice or environmental sound using its built-in microphone. 2. Playback Mode When the drawing stops, another squawk sound indicates the transition to playback mode. In this stage, the user squeezes the sponge with varying angles and pressure. The bending sensor detects these physical inputs, which are used to modulate the recorded audio in real time—changing its pitch, tone, or speed. Each squeeze generates a uniquely altered version of the sound. This two-step interaction enhances engagement by connecting gestures to sound transformation.

Design process

The design of Squack was guided by the visual language of playful brutalism, blending bold forms with approachable tactility. To support this, I created numerous sketches and mockups—exploring different sponge shapes, materials, and structures, from a playful water-bottle to modular support bases. From the start, I focused on making the product modular, stackable, and grabbable. The internal structure was designed to be modular and easily assembled, allowing components to be inserted and replaced. Various snap-fit and hinge mechanisms were tested to ensure stability while preserving flexibility. Throughout the process, I continually tested user interaction flow. To accommodate diverse users, I added both voice and music-based playback options. I also conducted multiple distance experiments to determine the optimal spacing between sensor and sponge surface for accurate gesture detection. The concept was iteratively refined with feedback loops between digital prototyping and physical trial. Each element—from the drawing trigger to the squeezing feedback—was considered through the lens of tactile clarity and emotional resonance. The result is a design that balances robustness with playfulness, offering a multisensory interaction that encourages exploration.

How it is different

While previous interactive sound projects like Noisy Jelly, Sound of Light, Ototo, and Singing Plant explored the link between physical input and auditory feedback, Squack introduces a more narrative, memory-oriented approach. It doesn’t merely react—it transforms. Unlike Ototo, which treats any object as a musical instrument, Squack builds an emotional connection by recording and replaying the user’s own voice, modulated through expressive squeezing. Compared to Singing Plant, which responds to passive touch, Squack places control in the user’s hands, allowing them to actively sculpt the sound output. Rather than translating environmental data into sound like Sound of Light, Squack links personal, intentional gestures—such as drawing and squeezing—to memory. The sponge serves as a metaphorical archive, where sounds are not simply played but reinterpreted each time.

Future plans

The next step is to enhance the overall product quality by refining material finishes, internal layout, and assembly precision. I plan to remake the outer structure with better tactile ergonomics and durability, while improving the visual appeal for presentation. Final documentation, high-resolution images, and a demo video will be produced to effectively communicate the concept. Additionally, I plan to prepare the project for exhibition, focusing on narrative clarity and user engagement during interaction.

Awards

2025 KAIST Ideafactory Prototyping Contest