ENGS 89/90 Reports



Degree Program


Year of Graduation


Project Advisor

Elizabeth Murnane


Solomon Diamond

Document Type


Publication Date



Over 37 million people in the United States who are deaf and/or hard of hearing are unable to seek emergency help via a conventional 911 voice call. text-911, a feature provided by cell-service providers, is the most promising market solution. However, text-911 is not compatible with 70% of 911 Public Safety Answering Points (PSAPs) in the US. accesSOS seeks to empower deaf people throughout the United States with a text-to-voice solution that lets them conveniently and directly reach 911 in emergencies. accesSOS has developed a progressive web application (PWA), accessible via smartphone browsers, that collects emergency information from users via an icon-based user interface (UI). Our ENGS 90 team prototyped a solution for converting the emergency information in the PWA into an audio message that is injected into a voice call relayed to the correct 911 PSAP. We use Twilio's Programmable Voice API to generate a voice call with a custom audio message, and we use Bandwidth’s Emergency Calling (EC) API to route the call to the appropriate 911 PSAP based on the user’s location at call-time. We refined the contents of the audio message after receiving feedback from four different 911 dispatchers from New Hampshire Emergency Services. We also performed end-to-end testing of the accesSOS PWA connected to our call routing code. We placed one successful live 911 test call where the call was routed to the correct PSAP, and the audio message was delivered over the call as expected. Our team succeeded in building a prototype for our sponsor that meets the primary design requirements.

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Restricted: Campus/Dartmouth Community Only Access

Available for download on Monday, March 24, 2025


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