diff --git a/ext/mixed/js/audio.js b/ext/mixed/js/audio.js
index 6a338cca..d2feae04 100644
--- a/ext/mixed/js/audio.js
+++ b/ext/mixed/js/audio.js
@@ -66,21 +66,6 @@ class TextToSpeechAudio {
             // NOP
         }
     }
-
-    static createFromUri(ttsUri) {
-        const m = /^tts:[^#?]*\?([^#]*)/.exec(ttsUri);
-        if (m === null) { return null; }
-
-        const searchParameters = new URLSearchParams(m[1]);
-        const text = searchParameters.get('text');
-        let voice = searchParameters.get('voice');
-        if (text === null || voice === null) { return null; }
-
-        voice = audioGetTextToSpeechVoice(voice);
-        if (voice === null) { return null; }
-
-        return new TextToSpeechAudio(text, voice);
-    }
 }
 
 class AudioSystem {
@@ -199,98 +184,3 @@ class AudioSystem {
         }
     }
 }
-
-
-function audioGetFromUrl(url, willDownload) {
-    const tts = TextToSpeechAudio.createFromUri(url);
-    if (tts !== null) {
-        if (willDownload) {
-            throw new Error('AnkiConnect does not support downloading text-to-speech audio.');
-        }
-        return Promise.resolve(tts);
-    }
-
-    return new Promise((resolve, reject) => {
-        const audio = new Audio(url);
-        audio.addEventListener('loadeddata', () => {
-            if (audio.duration === 5.694694 || audio.duration === 5.720718) {
-                // Hardcoded values for invalid audio
-                reject(new Error('Could not retrieve audio'));
-            } else {
-                resolve(audio);
-            }
-        });
-        audio.addEventListener('error', () => reject(audio.error));
-    });
-}
-
-async function audioGetFromSources(expression, sources, optionsContext, willDownload, cache=null) {
-    const key = `${expression.expression}:${expression.reading}`;
-    if (cache !== null) {
-        const cacheValue = cache.get(expression);
-        if (typeof cacheValue !== 'undefined') {
-            return cacheValue;
-        }
-    }
-
-    for (let i = 0, ii = sources.length; i < ii; ++i) {
-        const source = sources[i];
-        const url = await apiAudioGetUrl(expression, source, optionsContext);
-        if (url === null) {
-            continue;
-        }
-
-        try {
-            let audio = await audioGetFromUrl(url, willDownload);
-            if (willDownload) {
-                // AnkiConnect handles downloading URLs into cards
-                audio = null;
-            }
-            const result = {audio, url, source};
-            if (cache !== null) {
-                cache.set(key, result);
-            }
-            return result;
-        } catch (e) {
-            // NOP
-        }
-    }
-    return {audio: null, url: null, source: null};
-}
-
-function audioGetTextToSpeechVoice(voiceURI) {
-    try {
-        for (const voice of speechSynthesis.getVoices()) {
-            if (voice.voiceURI === voiceURI) {
-                return voice;
-            }
-        }
-    } catch (e) {
-        // NOP
-    }
-    return null;
-}
-
-function audioPrepareTextToSpeech(options) {
-    if (
-        audioPrepareTextToSpeech.state ||
-        !options.audio.textToSpeechVoice ||
-        !(
-            options.audio.sources.includes('text-to-speech') ||
-            options.audio.sources.includes('text-to-speech-reading')
-        )
-    ) {
-        // Text-to-speech not in use.
-        return;
-    }
-
-    // Chrome needs this value called once before it will become populated.
-    // The first call will return an empty list.
-    audioPrepareTextToSpeech.state = true;
-    try {
-        speechSynthesis.getVoices();
-    } catch (e) {
-        // NOP
-    }
-}
-audioPrepareTextToSpeech.state = false;