# Seeking Help with Speech-to-Text Implementation in Kepler WebView **URL:** \ **Category:** Q&A\ **Created:** [September 22, 2025, 9:06am UTC](https://community.amazondeveloper.com/t/seeking-help-with-speech-to-text-implementation-in-kepler-webview/20392 "2025-09-22T09:06:56Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Sergio\_Gomez](https://avatars.discourse-cdn.com/v4/letter/s/e47c2d/32.png) [@Sergio\_Gomez](https://community.amazondeveloper.com/u/Sergio_Gomez)\ **Post date:** [September 22, 2025, 9:06am UTC](https://community.amazondeveloper.com/t/seeking-help-with-speech-to-text-implementation-in-kepler-webview/20392/1 "2025-09-22T09:06:56Z")
We are currently working on implementing the speech-to-text functionality( [Web Speech API - Web APIs | MDN](https://developer.mozilla.org/en-US/docs/Web/API/Web_Speech_API#specifications) ) in Kepler WebView, but we’ve encountered some challenges. Despite following the documentation, we keep running into an issue where the `onerror` event triggers with the message ‘audio-capture’. Has anyone experienced this issue before or have any insights on how to resolve it? Any guidance or suggestions would be greatly appreciated. Thank you in advance for your help! ![busqueda_voz_error](https://d3mq594dkmpl37.cloudfront.net/original/2X/c/c0882f7c522ebfb8f7872652bfe84d947d726bde.png) ---
**Author:** ![Justin](https://dhm3gbtzu79o6.cloudfront.net/user_avatar/community.amazondeveloper.com/justin/32/585_2.png) [@Justin](https://community.amazondeveloper.com/u/Justin)\ **Post date:** [September 22, 2025, 7:16pm UTC](https://community.amazondeveloper.com/t/seeking-help-with-speech-to-text-implementation-in-kepler-webview/20392/3 "2025-09-22T19:16:40Z")
Hi @Sergio_Gomez, Thanks for reaching out! Based on a lookup of this error, it’s usually correlated to the common causes below. Did the team already investigate the causes below and were able to rule them out? - **User denies permission:** This is the most frequent reason. When a website requests microphone access, browsers display a prompt. If the user clicks “Block” or ignores the prompt, the promise returned by `getUserMedia()` is rejected, triggering the error. - **No microphone available:** The user’s device may not have a microphone or the hardware is disconnected, broken, or disabled in the operating system’s settings. The `getUserMedia()` API will reject the request with a `NotFoundError` in this case. - **Insecure context (not HTTPS):** Modern browsers require secure contexts (HTTPS) to access powerful web APIs like `getUserMedia()` for security and privacy. If the website is served over an insecure HTTP connection, the browser will block the request and reject the promise. - **Device is already in use:** The microphone may be in use by another application or tab, preventing the new request from succeeding. - **Blocked by permissions policy:** On some browsers, if the website’s permissions policy does not explicitly allow access to user media devices, the request will be denied. - **Browser-specific issues:** Less commonly, certain browser versions or operating system configurations can lead to the error. For example, older versions of Firefox once returned a `NotSupportedError` for empty constraint lists, which has since been corrected. ---
**Author:** ![Sergio\_Gomez](https://avatars.discourse-cdn.com/v4/letter/s/e47c2d/32.png) [@Sergio\_Gomez](https://community.amazondeveloper.com/u/Sergio_Gomez)\ **Post date:** [September 26, 2025, 2:00pm UTC](https://community.amazondeveloper.com/t/seeking-help-with-speech-to-text-implementation-in-kepler-webview/20392/5 "2025-09-26T14:00:51Z")
Hi Justin, Thanks for your previous reply. We’ve performed some additional tests and wanted to share the results for clarification: - When we call `navigator.mediaDevices.getUserMedia({ audio: true })`, we consistently get the error: **`NotSupportedError: NotSupported`**. - The app is running in a secure context (HTTPS). - A physical microphone is available on the device and not in use by any other application at the time of testing. - We never see a permission prompt for microphone access, so we’re not sure if permissions are being automatically denied in the Kepler WebView. - We also don’t know whether a permissions policy or a browser-specific limitation could be blocking access, and we don’t have a way to confirm this from our side. Given these points, we’re unsure how to properly access the microphone within Kepler. Could you confirm whether `getUserMedia` (and therefore audio capture) is supported in the Kepler environment, and if there are any additional steps required on our side to enable it? ---
**Author:** ![Ivy](https://dhm3gbtzu79o6.cloudfront.net/user_avatar/community.amazondeveloper.com/ivy/32/5637_2.png) [@Ivy](https://community.amazondeveloper.com/u/Ivy)\ **Post date:** [November 28, 2025, 6:41am UTC](https://community.amazondeveloper.com/t/seeking-help-with-speech-to-text-implementation-in-kepler-webview/20392/6 "2025-11-28T06:41:33Z")
Hi @Sergio_Gomez Can you use below alternatives? Either leverage chromium default Ax mechanism or use KeplerScript speech APIs. Do these options work for your usecase? Warm regards, Ivy ---
**Author:** ![Ivy](https://dhm3gbtzu79o6.cloudfront.net/user_avatar/community.amazondeveloper.com/ivy/32/5637_2.png) [@Ivy](https://community.amazondeveloper.com/u/Ivy)\ **Post date:** [December 15, 2025, 9:14am UTC](https://community.amazondeveloper.com/t/seeking-help-with-speech-to-text-implementation-in-kepler-webview/20392/7 "2025-12-15T09:14:16Z")
Hi @Sergio_Gomez Closing this ticket since there’s no reply from you. If you are still facing this issue, please feel free to create a new topic and we’ll be happy to help. Warm regards, Ivy ---
**Author:** ![Ivy](https://dhm3gbtzu79o6.cloudfront.net/user_avatar/community.amazondeveloper.com/ivy/32/5637_2.png) [@Ivy](https://community.amazondeveloper.com/u/Ivy)\ **Post date:** [December 15, 2025, 9:14am UTC](https://community.amazondeveloper.com/t/seeking-help-with-speech-to-text-implementation-in-kepler-webview/20392/8 "2025-12-15T09:14:21Z")