seanmiller98/duolingo-swahili-extension

Browser extension which provides text-to-speech audio for Swahili exercises on Duolingo # Duolingo Swahili+ # Chrome extension which provides audio recordings for the Swahili exercises on Duolingo. ## How does it Work? ## The way this extension works at a high level is like this: 1. Create a background script that waits for messages to be sent from a content script, and inject a content script into the webpage when the URL is of the form ...duolingo.com... 2. When the content script is injected into the webpage, create an HTML5 DOM MutationObserver which will get triggered whenever a mutation occurs to the webpage's DOM. 3. Detect whether the mutation involves the creation of a "Write this in English" test field. If it does, then send the text contained in the text field to the background script via a Chrome message. 4. The background script receives the text to output, creates a SpeechSynthesisUtterance object, and ouputs the audio. It then waits for the process to be repeated. ## But what about the Text-To-Speech problem? ## By far the trickiest challenge is outputting the text as speech; as of now, Chrome does not support TTS (text-to-speech) for Swahili, so my crazy work-around after lots of research on how to best approach this difficulty works as follows: 1. Convert the sentence into a collection of its syllables via a Swahili word syllable processing algorithm. 2. Slightly convert the syllables in order to be read properly... by the Indonesian TTS service provided by Chrome. 3. Output the syllables in quick enough succession by the Indonesian TTS that it sounds like a word. Yes, you read that right. After countless hours of trying to figure out the best way of working around the no-TTS-for-Swahili problem, I experimented with using the languages that ARE provided via the SpeechSynthesisUtterance API in HTML5 that cooperate with Chrome. It just so happens that, although Indonesian does a horrible job of pronouncing full words, it actually does a pretty decent job (with some adjustments, as described previously) of properly outputting the corre …