Transcribe streaming audio from a microphone in Python
Learn how to transcribe streaming audio in Python.
Overview
By the end of this tutorial, you’ll be able to transcribe audio from your microphone in Python.
Supported languages
Streaming Speech-to-Text is only available for English.
Before you begin
To complete this tutorial, you need:
- Python installed.
- An AssemblyAI account with a credit card set up.
Here’s the full sample code of what you’ll build in this tutorial:
Step 1: Install dependencies
Step 2: Configure the API key
In this step, you ‘ll create an SDK client and configure it to use your API key.
Browse to Account, and then click Copy API key under Copy your API key.
Step 3: Create a transcriber
In this step, you’ll set up a real-time transcriber object and callback functions that handle the different events.
Create another function to handle transcripts. The real-time transcriber returns two types of transcripts: RealtimeFinalTranscript and RealtimePartialTranscript.
- Partial transcripts are returned as the audio is being streamed to AssemblyAI.
- Final transcripts are returned after a moment of silence.
End of utterance controls
You can configure the silence threshold for automatic utterance detection and programmatically force the end of an utterance to immediately get a Final transcript.
Create a new RealtimeTranscriber
using the function you created.
Sample rate
The sample_rate
is the number of audio samples per second, measured in hertz (Hz). Higher sample rates result in higher quality audio, which may lead to better transcripts, but also more data being sent over the network.
We recommend the following sample rates:
- Minimum quality:
8_000
(8 kHz) - Medium quality:
16_000
(16 kHz) - Maximum quality:
48_000
(48 kHz)
Step 4: Connect the transcriber
Streaming Speech-to-Text uses WebSockets to stream audio to AssemblyAI. This requires first establishing a connection to the API.
The on_open
function you created earlier will be called when the connection has been established.
Step 5: Record audio from microphone
In this step, you’ll configure your Python app to record audio from your microphone. You’ll use a helper class from the Python SDK that make this easier.
Open a microphone stream. The sample_rate
needs to be the same value as the one you passed to RealtimeTranscriber
.
Audio data format
MicrophoneStream
formats the audio data for you. If you want to stream data from elsewhere, make sure that your audio data is in the following format:
- Single channel
- 16-bit signed integer PCM or mu-law encoding
By default, transcriptions expect PCM16-encoded audio. If you want to use mu-law encoding, see Specifying the encoding.
Step 6: Close the connection
Finally, close the connection when you’re done to disconnect the transcriber.
The on_close
function you created earlier will be called when the connection has been closed.
Next steps
To learn more about Streaming Speech-to-Text, see the following resources:
Need some help?
If you get stuck, or have any other questions, we’d love to help you out. Contact our support team at support@assemblyai.com or create a support ticket.