Hello PAVAGEAU Perrine ,
Thanks for your question.
Currently, Azure AI Speech does not support incremental training, which means you cannot simply add new data to an existing model without retraining the entire model from scratch. When you update your dataset and retrain, the system will include all previous data along with the newly added data, resulting in the same approximate 24-hour training time. To manage this, consider accumulating larger batches of new data before retraining, ensuring the new data is of high quality, and automating the data preparation and training initiation process using tools like Azure DevOps. After each training iteration, evaluate the model's performance with a validation dataset to understand the impact of the new data.
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