Microsoft Skype just expanded its feature allowing users to translate their speech in real time. The company announced that Skype Translator, previously only available for calls made between one Skype client and another, will now include all calls to mobile phones and landlines.

The Translator feature currently supports nine spoken languages: English, Spanish, French, German, Mandarin Chinese, Italian, Brazilian Portuguese, Arabic, and Russian. That represents a sizeable chunk of the native languages spoken by the world's population. But the feature is still far from perfect. The company said it recommends that callers use headsets to improve translation quality.

Additionally, since the translation algorithm is being driven by deep learning programs, the system is only as good as the size of its data set. While Translator has been learning from users since 2014, Skype said the quality of the translations would continue to improve gradually as more people use it.