SignBridge

SignBridge

UI design mockup for the SignBridge sign language translation app, showing the main recording screen on a mobile phone.

Role:

Product Designer

Client:

Conceptual Project

Time:

May 2026

Create a Concept for an Application for Real-Time Translation of German Sign Language (DGS)

1. Overview

The Challenge

In everyday spontaneous communication between deaf or hard-of-hearing individuals and hearing individuals a severe communication barrier persists. Human interpreters are unavailable and existing apps address this problem insufficiently, as they are mostly unidirectional or rely on written language as an alternative.

The Solution

A highly accessible mobile concept combining edge-AI tracking with collaborative UX design to enable fast, barrier-free communication.

2. Project Scope & Problem

Business Goals

Conceptualize a viable, accessible digital bridge for the deaf and hard-of-hearing (DHH) community as an academic capstone (€0 budget).

User Pain Points

Deaf individuals face high friction in time-critical situations (e.g., bakeries, checkouts). Existing 3D avatars lack crucial facial expressions, falling into the "uncanny valley" and causing community rejection.

Constraints

The project faced severe limitations: a massive lack of open-source DGS training data, strict GDPR biometric privacy rules, and the physical clash between a handheld device and a two-handed language.

Conceptual illustration depicting a communication barrier between a person with question marks above their head and a person using sign language, separated by a jagged red line and an X.
Conceptual illustration depicting a communication barrier between a person with question marks above their head and a person using sign language, separated by a jagged red line and an X.
The Problem: The communication barrier between spoken and sign languages.

3. Research and Strategy

Key Findings

  • Spatial Grammar: DGS is not spoken German; it has a unique syntax.

  • Facial Nuance: Up to 20% of grammatical meaning relies on facial expressions. Tracking only hands is linguistically insufficient.

  • Privacy by Design: Tracking faces requires processing sensitive biometric data (GDPR). AI processing must happen locally (Edge AI).

Archetypes / Personas

The primary persona requires fast, visual, and tactile feedback. Text-heavy interfaces cause cognitive strain because written German functions as an unfamiliar second language.

Problem Redefinition

The challenge shifted from simply "translating gestures" to capturing holistic spatial data while designing a collaborative interface that hearing partners can easily operate.

4. Ideation and Iteration

Architecture and Flows

A flat hierarchy with a dominant "One-Button" interaction minimizes cognitive load and allows instant access to the core translation flow.

Trade-offs

A critical trade-off involved the physical impossibility of signing with both hands while holding a smartphone. Instead of forcing a flawed technical workaround, the design pivoted to a collaborative model: optimizing the interface so the hearing partner can easily hold the device and keep the camera framed.

Testing and Refinement

Global navigation causes visual noise during high-stress interactions. The design was iterated to feature "Distraction-Free Tunneling," completely hiding the tab bar inside a full-screen modal during active translation.

Four mobile wireframe screens arranged horizontally, illustrating the user flow for a sign language translation app, from the initial recording screen to camera tracking, text translation output, and a 3D avatar response screen.
Four mobile wireframe screens arranged horizontally, illustrating the user flow for a sign language translation app, from the initial recording screen to camera tracking, text translation output, and a 3D avatar response screen.
Initial Wireframes: Mapping out the core user flow and translation steps.

5. Final Design

Home & Input

The dark slate UI reduces visual glare and cognitive fatigue for prolonged visual attention. On the camera screen, a simulated AI overlay provides real time feedback, confirming that the system is successfully tracking both hands and lips.

Output & Avatar

High-contrast cards ensure the hearing partner can read text from a distance. The 3D avatar emphasizes distinct facial expressions for grammatical accuracy.

Interactions

Auditory feedback is replaced with "Semantic Haptics." System states (e.g., "camera ready," "hands out of frame") are communicated through distinct, learnable vibration patterns.

Design System

Strictly adheres to POUR accessibility frameworks and meets the WCAG AA contrast standards, utilizing highly legible typography.

Four dark-themed high-fidelity mobile screens of the final design, arranged horizontally and showing the complete translation flow of the SignBridge app: the start screen, live camera sign language tracking with yellow overlays, the text translation output, and a 3D animated avatar signing the response.
Four dark-themed high-fidelity mobile screens of the final design, arranged horizontally and showing the complete translation flow of the SignBridge app: the start screen, live camera sign language tracking with yellow overlays, the text translation output, and a 3D animated avatar signing the response.
The Solution: Final interface designs for the SignBridge translation ecosystem.

6. Outcomes and Learnings

Measuring Cognitive Load

To establish a baseline for the main workflow, an internal evaluation was conducted using the NASA Task Load Index (NASA-TLX).

Estimated Workload Range: 25 – 36 / 100 (Low Friction)

  • Low Cognitive Strain: The linear "One-Button" layout and full-screen tunneling successfully minimize mental demand and frustration.

  • Physical Demand Realism: The index isolates physical exertion as the primary workload contributor, accurately reflecting the expressive nature of DGS.

  • Performance Confidence: The real-time AI tracking mesh provides immediate visual reassurance, reducing user anxiety regarding system accuracy.

This range serves as an initial walkthrough baseline. Empirical user testing with the deaf and hard-of-hearing (DHH) community is required in the next phase to capture authentic real-world cognitive loads.

Challenges Overcome

Navigated the contradiction between a two-handed language and a handheld device by shifting the UX focus to a collaborative, dual-user interaction model.

Reflection

An appealing user interface is only a small part of accessibility technology. Even though this concept still seems somewhat utopian at present due to enormous technical and financial hurdles, supporting marginalized communities remains of crucial importance. Even if only about 0.1% of the population in Germany uses DGS, the impact on independence in everyday life makes the continued development of such inclusive technology absolutely essential.

Next Steps

Transporting this concept into the future, a logical evolution could be expanding the mobile application into a B2B "Kiosk Mode." Partnering with retail chains to integrate the software into stationary counter tablets would completely eliminate the need to hold a device. This structural integration frees both hands for grammatically perfect communication and provides a scalable, systemic solution to the physical limitations of mobile hardware.

© 2026 Marius Neumann

© 2026 Marius Neumann

© 2026 Marius Neumann