This topic describes the parameters and interfaces of the Python SDK for the Qwen-Audio-3.0-ASR-Flash-Streaming/Fun-ASR-Realtime real-time speech recognition model.
Alibaba Cloud Model Studio has released workspace-specific domains for the China (Beijing) and Singapore regions. The new dedicated domains deliver superior performance and higher stability for inference requests. We recommend migrating to the new domains:
China (Beijing): from
dashscope.aliyuncs.comto{WorkspaceId}.cn-beijing.maas.aliyuncs.comSingapore: from
dashscope-intl.aliyuncs.comto{WorkspaceId}.ap-southeast-1.maas.aliyuncs.com
Replace {WorkspaceId} with your actual Workspace ID. The existing domains remain fully functional.
User guide: For model descriptions and selection guidance, see Speech-to-text.
Prerequisites
The service is activated and Obtain an API key. To guard against security risks caused by code leaks, Configure API key as an environment variable, rather than hard-coding it in your code.
Quick start
The Recognition class provides interfaces for both non-streaming and bidirectional streaming calls. Choose the call method that fits your needs:
-
Non-streaming call: Recognizes a local file and returns the complete result in a single response. Suitable for processing pre-recorded audio.
-
Bidirectional streaming call: Recognizes an audio stream directly and outputs results in real time. The audio stream can come from an external device, such as a microphone, or be read from a local file. Suitable for scenarios that require immediate feedback.
Non-streaming call
Submit a single real-time speech recognition task and get the recognition result synchronously by passing in a local file.
Instantiate a Recognition class, bind a Request parameters, and call call to run recognition or translation and get the final Recognition result (RecognitionResult).
Bidirectional streaming call
Submit a single real-time speech recognition task and stream the real-time recognition results by implementing the callback interface.
-
Start streaming speech recognition.
Instantiate a Recognition class, bind a Request parameters and a Callback interface (RecognitionCallback), and call the
startmethod to start streaming speech recognition. -
Stream the audio.
Call the
send_audio_framemethod of the Recognition class in a loop to send the binary audio stream to the server in segments. The stream is read from a local file or a device, such as a microphone.While the audio is being sent, the server returns recognition results to the client in real time through the
on_eventmethod of the Callback interface (RecognitionCallback).Send about 100 ms of audio per frame, and keep each frame between 1 KB and 16 KB.
-
End the task.
Call the
stopmethod of the Recognition class to end speech recognition.This method blocks the current thread until the
on_completeoron_errorcallback of the Callback interface (RecognitionCallback) is triggered.
Request parameters
Set request parameters through the constructor (_init_) of the Recognition class.
|
Parameter |
Type |
Required |
Description |
|
model |
str |
Yes |
The model name. The Qwen-Audio-3.0-ASR-Flash-Streaming and Fun-ASR-Realtime model series are supported. For details, see Supported models and regions. |
|
sample_rate |
int |
Yes |
The sample rate, in Hz. Valid values: 8 kHz models support only 8000 Hz; other models support any sample rate. |
|
format |
str |
Yes |
The audio format. Valid values:
Important
opus/speex: Must use Ogg encapsulation. wav: Must use PCM encoding. amr: Only the AMR-NB type is supported. |
|
vocabulary_id |
str |
No |
The ID of a precompiled hot word list. Generate this ID in advance by calling the create hot word list API. Pass the ID during recognition to use the hot words in the list. Suitable for scenarios where the vocabulary is known and relatively stable, and where you need to reuse the same word list across requests. For usage details, see Precompiled hotwords. |
|
vocabulary |
dict |
No |
Instant hot words. Passed as key-value pairs, where the key is the hot word text ( Suitable for temporary, session-level hot word optimization. When configured together with precompiled hot words, only the instant hot words take effect. For usage details, see Instant hotwords. Important
Only Example:
|
|
semantic_punctuation_enabled |
bool |
No |
Whether to enable semantic segmentation. Default: False.
Semantic segmentation is more accurate and suits meeting transcription. VAD (Voice Activity Detection) segmentation has lower latency and suits interactive scenarios. |
|
max_sentence_silence |
int |
No |
The VAD silence threshold for segmentation, in ms. When the silence after a segment of speech exceeds this threshold, the system determines that the sentence has ended. When Default value: 1300. Valid values: [200, 6000]. |
|
multi_threshold_mode_enabled |
bool |
No |
Important
Takes effect only when Whether to enable multi-threshold mode. When enabled, it prevents VAD segmentation from producing segments that are too long. Default: False. |
|
punctuation_prediction_enabled |
bool |
No |
Whether to automatically add punctuation to recognition results:
|
|
heartbeat |
bool |
No |
Whether to enable heartbeat packets. Default: False.
Silent audio refers to content in an audio file or data stream that contains no sound signal. You can generate silent audio in several ways, such as using audio editing software like Audacity or Adobe Audition, or using a command-line tool like FFmpeg. This field requires SDK version 1.23.1 or later. |
|
language_hints |
list[str] |
No |
The language of the audio to recognize. There is no default value; if not set, the model detects the language automatically. For the Qwen-Audio-3.0-ASR-Flash-Streaming model series, you can set up to 4 values; if you set more than 4, only the first 4 take effect. For the Fun-ASR-Realtime model series, you can set only 1 value; if you set multiple values, only the first one takes effect. |
|
speech_noise_threshold |
float |
No |
The threshold for distinguishing speech from noise, used to adjust the sensitivity of Voice Activity Detection (VAD). Valid values: [-1.0, 1.0]. Value descriptions:
This is an advanced configuration parameter. Adjusting it can significantly affect recognition results. Recommendations:
|
|
special_word_filter |
str |
No |
Specifies the sensitive words to process during speech recognition, and supports setting different processing methods for different sensitive words. For details, see Sensitive word filtering. |
|
callback |
RecognitionCallback |
No |
Pass the following parameters as keyword arguments to the call or start method of the Recognition instance.
|
Parameter |
Type |
Required |
Description |
|
raw_input |
dict |
No |
The input object used to pass in the conversation context. Context enhancement improves recognition accuracy for domain-specific terms. For usage, see Quick start. Important
The context parameter is supported only by the The dict must include a
Important
Limits: Context messages of the Important
When you pass context, the messages in Note
This field requires SDK version 1.25.23 or later. Pass
|
Key interfaces
Recognition class
Import Recognition with "from dashscope.audio.asr import *".
|
Member method |
Method signature |
Description |
|
call |
|
A non-streaming call based on a local file. This method blocks the current thread until all audio is read, and requires read permission on the file. The recognition result is returned as a |
|
start |
|
Starts speech recognition. A callback-based streaming real-time recognition. This method does not block the current thread. Use it together with |
|
send_audio_frame |
|
Pushes audio. Keep each pushed audio frame neither too large nor too small: about 100 ms per frame, between 1 KB and 16 KB. Recognition results are obtained through the on_event method of the Callback interface (RecognitionCallback). |
|
stop |
|
Stops speech recognition. Blocks until the server finishes recognizing all received audio, then ends the task. |
|
get_last_request_id |
|
Gets the request_id. Available after the constructor is called (the object is created). |
|
get_first_package_delay |
|
Gets the first-packet delay: the latency from sending the first audio packet to receiving the first recognition result. Use it after the task completes. |
|
get_last_package_delay |
|
Gets the last-packet delay: the time from sending the |
|
get_response |
|
Gets the last message. Use it to retrieve a task-failed error. |
Callback interface (RecognitionCallback)
During a Bidirectional streaming call, the server returns key process information and data to the client through callbacks. Implement the callback methods to handle the information and data returned by the server.
|
Method |
Parameter |
Return value |
Description |
|
None |
None |
Called immediately after the connection to the server is established. |
|
None |
Called when the server has a response. |
|
|
None |
None |
Called after all recognition results are returned. |
|
None |
Called when an error occurs. |
|
|
None |
None |
Called after the server closes the connection. |
Response
Recognition result (RecognitionResult)
RecognitionResult represents the result of a single real-time recognition in a Bidirectional streaming call, or the result of a Non-streaming call.
|
Member method |
Method signature |
Description |
|
get_sentence |
|
Gets the current recognized sentence and its timestamp information. A callback returns a single sentence, so this method returns Dict[str, Any]. For details, see Sentence (Sentence). |
|
get_request_id |
|
Gets the request_id of the request. |
|
is_sentence_end |
|
Determines whether the given sentence has ended. This method checks whether the |
Sentence information (Sentence)
The members of the Sentence class are as follows:
|
Parameter |
Type |
Description |
|
begin_time |
int |
Sentence start time, in ms. |
|
end_time |
int |
Sentence end time, in ms. |
|
text |
str |
Recognized text. |
|
words |
A list of Word-level timestamp information (Word) |
Word-level timestamp information. |
Word-level timestamp information (Word)
The members of the Word class are as follows:
|
Parameter |
Type |
Description |
|
begin_time |
int |
Word start time, in ms. |
|
end_time |
int |
Word end time, in ms. |
|
text |
str |
The word. |
|
punctuation |
str |
The punctuation. |
Error codes
If you encounter errors, see Error codes for troubleshooting.
If the issue persists, join the developer community to report your issue and provide the Request ID for further investigation.
FAQ
Features
Q: How do I keep the connection alive during long periods of silence?
Set the heartbeat request parameter to true, and keep sending silent audio to the server.
Silent audio is content in an audio file or stream that contains no sound signal. You can generate silent audio in several ways, such as using audio editing software like Audacity or Adobe Audition, or command-line tools like FFmpeg.
Q: How do I convert audio to a supported format?
Use FFmpeg. For more usage, see the FFmpeg official website.
# Basic conversion command (all-purpose template)
# -i, purpose: input file path, example value: audio.wav
# -c:a, purpose: audio codec, example values: aac, libmp3lame, pcm_s16le
# -b:a, purpose: bitrate (audio quality control), example values: 192k, 320k
# -ar, purpose: sample rate, example values: 44100 (CD), 48000, 16000
# -ac, purpose: number of channels, example values: 1 (mono), 2 (stereo)
# -y, purpose: overwrite an existing file (no value needed)
ffmpeg -i input_audio.ext -c:a codec_name -b:a bitrate -ar sample_rate -ac channels output.ext
# For example: WAV to MP3 (keep the original quality)
ffmpeg -i input.wav -c:a libmp3lame -q:a 0 output.mp3
# For example: MP3 to WAV (16-bit PCM standard format)
ffmpeg -i input.mp3 -c:a pcm_s16le -ar 44100 -ac 2 output.wav
# For example: M4A to AAC (extract or convert Apple audio)
ffmpeg -i input.m4a -c:a copy output.aac # Extract directly without re-encoding
ffmpeg -i input.m4a -c:a aac -b:a 256k output.aac # Re-encode to improve quality
# For example: FLAC lossless to Opus (high compression)
ffmpeg -i input.flac -c:a libopus -b:a 128k -vbr on output.opus
Q: How do I recognize a local file (recording)?
There are two ways to recognize a local file:
-
Pass the local file path directly: This way returns the complete result only after recognition finishes, so it isn't suitable for scenarios that need immediate feedback.
See Non-streaming call, and pass the file path to the
callmethod of the Recognition class to recognize the recording directly. -
Convert the local file to a binary stream for recognition: This way recognizes the file while streaming results, so it suits scenarios that need immediate feedback.
See Bidirectional streaming call, and send the binary stream to the server for recognition through the
send_audio_framemethod of the Recognition class.
Troubleshooting
Q: Why can't the speech be recognized (no recognition result)?
-
Check that the audio format (
format) and sample rate (sampleRate/sample_rate) in the request parameters are correct and meet the parameter constraints. Common errors include:-
The audio file has a .wav extension but is actually in MP3 format, while the
formatrequest parameter is set to mp3 (incorrect parameter setting). -
The audio sample rate is 3600 Hz, but the
sampleRate/sample_raterequest parameter is set to 48000 (incorrect parameter setting).
Use the ffprobe tool to get the container, codec, sample rate, channels, and other information of the audio:
ffprobe -v error -show_entries format=format_name -show_entries stream=codec_name,sample_rate,channels -of default=noprint_wrappers=1 input.xxx -
-
If none of the checks above reveal a problem, add custom hotwords to improve recognition of specific terms.