Changelog
Follow along to see weekly accuracy and product improvements.
April 4, 2022
Spanish Language Support, Automatic Language Detection, and Custom Spelling Released
- Spanish transcription is now publicly available. Check out our documentation for more information on Specifying a Language in your
POSTrequest. - Automatic Language Detection is now available for our
/v2/transcriptendpoint. This feature can identify the dominant language that’s spoken in an audio file and route the file to the appropriate model for the detected language. - Our new Custom Spelling feature gives you the ability to specify how words are spelled or formatted in the transcript text. For example, Custom Spelling could be used to change all instances
"CS 50"to"CS50".
March 28, 2022
Auto Chapters v6 Released
- Released Auto Chapters v6, improving the summarization of longer chapters.
March 14, 2022
Auto Chapters v5 Released
- Auto Chapters v5 released, improving
headlineandgistgeneration and quote formatting in thesummarykey.
- Fixed an edge case in Dual-Channel files where initial words in an audio file would occasionally be missed in the transcription.
March 8, 2022
Regional Spelling Improvements
- Region-specific spelling improved for
en_ukanden_aulanguage codes. - Improved the formatting of “MP3” in transcripts.
- Improved Real-Time transcription error handling for corrupted audio files.
February 28, 2022
Real-Time v3 Released
- Released v3 of our Real-Time Transcription model, improving overall accuracy by 18% and proper noun recognition by 23% relative to the v2 model.
- Improved PII Redaction and Entity Detection for
CREDIT_CARD_CVVandLOCATION.
February 22, 2022
Auto Chapters v4 Released, Auto Retry Feature Added
- Added an Auto Retry feature, which automatically retries transcripts that fail with a
Server error, developers have been alertedmessage. This feature is enabled by default. To disable it, visit the Account tab in your Developer Dashboard.
- Auto Chapters v4 released, improving chapter summarization in the
summarykey. - Added a trailing period for the
gistkey in the Auto Chapters feature.
February 7, 2022
Auto Chapters v3 Released
- Released v3 of our Auto Chapters model, improving the model’s ability to segment audio into chapters and chapter boundary detection by 56.3%.
- Improved formatting for Auto Chapters summaries. The
summary,headline, andgistkeys now include better punctuation, casing, and text formatting.
January 31, 2022
Miscellaneous Bug Fixes
- Fixed a rare edge case affecting audio duration calculation of a small percentage of multi-channel files that contained no speech.
- Miscellaneous bug fixes for Real-Time Transcription.
January 24, 2022
Webhook Status Codes, Entity Detection Improved
POSTrequests from the API to webhook URLs will now accept any status code from200to299as a successful HTTP response. Previously only200status codes were accepted.- Updated the
textkey in our Entity Detection feature to return the proper noun rather than the possessive noun. For example,Andrewinstead ofAndrew’s.
- Fixed an edge case with Entity Detection where under certain contexts, a disfluency could be identified as an entity.
January 17, 2022
Punctuation and Casing Accuracy Improved, Inverse Text Normalization Model Updated
- Released v4 of our Punctuation model, increasing punctuation and casing accuracy by ~2%.
- Updated our Inverse Text Normalization (ITN) model for our
/v2/transcriptendpoint, improving web address and email address formatting and fixing the occasional number formatting issue.
- Fixed an edge case where multi-channel files would return no text when the two channels were out of phase with each other.
January 10, 2022
Support for Non-English Languages Coming Soon
- Our Deep Learning team has been hard at work training our new non-English language models. In the coming weeks, we will be adding support for French, German, Italian, and Spanish.
January 3, 2022
Shorter Summaries Added to Auto Chapters, Improved Filler Word Detection
- Added a new
gistkey to the Auto Chapters feature. This new key provides an ultra-short, usually 3 to 8 word summary of the content spoken during that chapter.

- Implemented profanity filtering into Auto Chapters, which will prevent the API from generating a
summary,headline, orgistthat includes profanity. - Improved Filler Word (aka, disfluencies) detection by ~5%.
- Improved accuracy for Real-Time Streaming Transcription.
- Fixed an edge case where WebSocket connections for Real-Time Transcription sessions would occasionally not close properly after the session was terminated. This resulted in the client receiving a 4031 error code even after sending a session termination message.
- Corrected a bug that occasionally attributed disfluencies to the wrong utterance when Speaker Labels or Dual-Channel Transcription was enabled.
December 27, 2021
v8.5 Asynchronous Transcription Model Released
- Our Asynchronous Speech Recognition model is now even better with the release of v8.5.
- This update improves overall accuracy by 4% relative to our v8 model.
- This is achieved by improving the model’s ability to handle noisy or difficult-to-decipher audio.
- The v8.5 model also improves Inverse Text Normalization for numbers.
December 20, 2021
New and Improved API Documentation
- Launched the new AssemblyAI Docs, with more complete documentation and an easy-to-navigate interface so developers can effectively use and integrate with our API. Click here to view the new and improved documentation.
- Added two new fields to the
FinalTranscriptresponse for Real-time Transcriptions. Thepunctuatedkey is a Boolean value indicating if punctuation was successful. Thetext_formattedkey is a Boolean value indicating if Inverse Text Normalization (ITN) was successful.
December 13, 2021
Inverse Text Normalization Added to Real-Time, Word Boost Accuracy Improved
- Inverse Text Normalization (ITN) added for our
/v2/realtimeand/v2/streamendpoints. ITN improves formatting of entities like numbers, dates, and proper nouns in the transcription text.
- Improved accuracy for Custom Vocabulary (aka, Word Boosts) with the Real-Time transcription API.
- Fixed an edge case that would sometimes cause transcription errors when
disfluencieswas set totrueand no words were identified in the audio file.
December 4, 2021
Entity Detection Released, Improved Filler Word Detection, Usage Alerts
- v1 release of Entity Detection - automatically detects a wide range of
entitieslike person and company names, emails, addresses, dates, locations, events, and more. - To include Entity Detection in your transcript, set
entity_detectiontotruein your POST request to/v2/transcript. - When your transcript is complete, you will see an
entitieskey towards the bottom of the JSON response containing the entities detected, as shown here:

- Read more about Entity Detection in our official documentation.
- Usage Alert feature added, allowing customers to set a monthly usage threshold on their account along with a list of email addresses to be notified when that monthly threshold has been exceeded. This feature can be enabled by clicking “Set up alerts” on the “Developers” tab in the Dashboard.

- When Content Safety is enabled, a summary of the severity scores detected will now be returned in the API response under the
severity_score_summarynested inside of thecontent_safety_labelskey, as shown below.

- Improved Filler Word (aka, disfluencies) detection by ~25%.
- Fixed a bug in Auto Chapters that would occasionally add an extra space between sentences for headlines and summaries.
November 27, 2021
Additional MIME Type Detection Added for OPUS Files
- Added additional MIME type detection to detect a wider variety of OPUS files.
- Fixed an issue with word timing calculations that caused issues with speaker labeling for a small number of transcripts.
November 23, 2021
Custom Vocabulary Accuracy Significantly Improved
- Significantly improved the accuracy of Custom Vocabulary, and the impact of the
boost_paramfield to control the weight for Custom Vocabulary. - Improved precision of word timings.
November 12, 2021
New Auto Chapters, Sentiment Analysis, and Disfluencies Features Released
- v1 release of Auto Chapters - which provides a "summary over time" by breaking audio/video files into "chapters" based on the topic of conversation. Check out our blog to read more about this new feature. To enable Auto Chapters in your request, you can set
auto_chapters: truein your POST request to/v2/transcript. - v1 release of Sentiment Analysis - that determines the sentiment of sentences in a transcript as
"positive","negative", or"neutral". Sentiment Analysis can be enabled by including thesentiment_analysis: trueparameter in your POST request to/v2/transcript. - Filler-words like
"um"and"uh"can now be included in the transcription text. Simply includedisfluencies: truein your POST request to/v2/transcript.
- Deployed Speaker Labels version 1.3.0. Improves overall diarization/labeling accuracy.
- Improved our internal auto-scaling for asynchronous transcription, to keep turnaround times consistently low during periods of high usage.
November 7, 2021
New Language Code Parameter for English Spelling
- Added a new
language_codeparameter when making requests to/v2/transcript. - Developers can set this to
en_us,en_uk, anden_au, which will ensure the correct English spelling is used - British English, Australian English, or US English (Default). - Quick note: for customers that were historically using the
assemblyai_en_auorassemblyai_en_ukacoustic models, thelanguage_codeparameter is essentially redundant and doesn't need to be used.

- Fixed an edge-case where some files with prolonged silences would occasionally have a single word predicted, such as "you" or "hi."