Frequently Asked Questions about the Speechly SLU platform and API.

Building models

  • What are SLU rules? The SLU rules define the SLU model. The model is configured through sample utterances that are annotated using our custom syntax.

  • What is an utterance? An utterance is something that the end-user says. It can consist of one or more segments. See SLU Examples.

  • How many SLU rules/utterances do I need to train my models with? It depends fully on the complexity of the model. If your model is only trained to turn the lights on and off, probably 50 lines of utterances is already a pretty good amount. For any more complex application, the number of sample utterances should rather be in thousands.

  • What is application ID and how do I use it? An application ID is needed to build an access token for the Speechly API. You can find your application ID in the Speechly Dashboard. The application ID should not be shared publicly, because it allows others to access your model. If you fear your application ID has leaked, you can either delete the application or ask us to revoke access to it.

  • How do I test my model in practice? You can test your model in the Speechly Playground, and share access to it in our Dashboard.

  • How long does it take to the train the model? It depends heavily on the number of SLU rules. It shouldn’t take more than 5 minutes with most setups, but if you have thousands of lines of rules, it can take longer. You will get a notification once the training is completed.

  • How do I share my model for someone else to test it? You can do this easily in the Playground window by clicking the Share button located on the top right corner. When you share the model, you are asked to set the visibility of your app to public and describe the app’s purpose so that the users know what it’s intended to be used for.

  • How do I connect my client to the model I’ve built? The Speechly API can be called from whatever device or platform. To do this, please review the API Reference to see how to call the API and receive responses. We have also created ready-made libraries / SDKs that help you connect clients on the most popular platforms to the API. You can find documentation for client libraries here.

  • How can I evaluate the performance of my model? We will launch our more advanced analytics features shortly, but in the meanwhile, you can test your model in the Speechly Playground.

User data

  • How do I delete my data? You can delete all user data from the Admin Dashboard. If you want a verification that all data is deleted, you can contact privacy@speechly.com

  • How is my data protected? We protect all data using industry best practices. Speechly can use the data you provide us to train our own models in free tier. You can revisit our privacy policy here.

Developing on Speechly

  • How can I find my Speechly API token for command line tool? You can find your API token under Project Settings. Remember that you need to save the token as there’s no way to see it after you’ve created it.
  • How can I integrate Speechly to my app? The easiest way to start developing on Speechly is to use our client libraries

  • How can I integrate Speechly to my app built on another platform? You can either use our API reference or contact us.

  • What is device ID and why do I need that? The device ID is a unique identifier for the end-user device. It is used in our API to differentiate between the different devices that use the model. The application ID is used to adapt the speech recognition to the particular acoustic properties of the microphone on the device, the speaker, and the usage context of the application. Keeping this ID persistent and distinct for each user/device will significantly improve the accuracy of the voice user experience.

  • The microphone doesn’t work on iOS and Mobile Safari? iOS doesn’t allow asking for microphone permissions on the page load, but rather, after user interaction. While some browsers might support other patterns, this is the best practice on all browsers, because the user should explicitly initiate the action that requires a microphone. If the permissions are asked on the page load, the user might not understand why it is needed, and may simply deny access.


  • Why I’m getting bad results on browser? If you are experiencing bad speech recognition results on browser clients (React and browser) it’s probably due to corrupted audio. As Speechly is optimized for low latency and real-time audio, the audio can become corrupted if the main thread is blocked for too long times.

Make sure your application’s main thread is not blocked by moving all resource heavy computation to other threads by using Web Workers.

  • Why are my intents and entities not recognized correctly? The Speechly SLU model is based on machine learning. If your intents and entities are not recognized correctly, we recommend you to add more training rules (i.e., example utterances) to the configuration that contain those intents and entities. Then try again.

  • I’m having a weird issue and can’t find the answer from the documentation, or the documentation is not correct. Please send us an email and we can help you forward.

  • Why do I get “Mic consent denied” error in the Playground? Why doesn’t my microphone work in the Playground? Once you start the Playground, you’ll have to click on Tap to start and give permissions for your browser to access the microphone. Here’s a short clip that shows the process:

If you have denied access to the microphone and don’t get the dialog for microphone permissions, see these browser-specific instructions:

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Last updated by Antti Ukkonen on April 7, 2021 at 18:29 +0300

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