Scenario: Speed-D Delivery is run by Barry Allen out of its Global Corporate Headquarters in Florence Italy. He has hired Diana Prince as for a series of Azure AI Services projects. Speed-D has an app that sends audio recordings from a call centre to the speech-to-text feature of Azure AI Services. During testing, Diana notices that the Word Error Rate (WER) is high and there are a lot of substitution errors. Barry has tasked Diana with improving the model and reduce the WER. What should Diana add to the training data to improve the model and reduce the WER?