TrailPulse: An Offline-First Spatial Audio Guide for Zero Screen-Time Outdoors

Description and use

TrailPulse offers an offline spatial audio guide, letting hikers listen to location‑based narratives through earbuds without screens or internet.

Problem

Outdoor apps that enrich nature experiences often require constant visual attention and rely on cellular connectivity, which is unavailable in many backcountry trails.

Outcome

TrailPulse enables hikers to experience spatial audio guides without screens or internet, improving immersion and reliability in remote trails.

Workflow

• Prepare GPX track at home
• Upload GPX to TrailPulse server
• Server queries Overpass API for POIs
• Generate sensory scripts with Gemma 2 via Ollama
• Convert scripts to audio with ElevenLabs TTS
• Package audio and manifest into a ZIP bundle
• Download bundle to device
• Unpack ZIP with JSZip, store audio in IndexedDB
• During hike, navigator.geolocation polls GPS
• Haversine proximity check triggers alerts within 25–40m
• Play audio vignette through earbuds
• Lock‑screen MediaSession displays landmark name and pause/resume controls

Evidence

TrailPulse is an offline‑first Progressive Web App (PWA) that converts standard GPX routes into location‑triggered spatial audio narratives.

Source

Dynamic Haversine geofencing continuously monitors satellite coordinates in the background.

Source

Gemma 2 was prompted to write concise, 30–45 word sensory scripts focusing strictly on physical touchpoints.

Source