Hinglish Text to Speech: The Code-Switching Challenge
Most people in India don't speak pure Hindi or pure English — they switch between both mid-sentence. This mixing, known as code-switching, is one of the hardest problems in text-to-speech.
Why it's hard
A traditional TTS engine is trained on one language at a time. Feed it a sentence like "Mujhe ye project Monday tak submit karna hai" and it either mispronounces the English words with a heavy Hindi accent, or mispronounces the Hindi words entirely — because it was never trained to expect both in the same breath.
Script helps, but isn't everything
One practical signal is script: if a sentence contains Devanagari characters, it's very likely Hindi or Hinglish, even if some words are written in Latin script. Routing that whole sentence to a Hindi-aware engine tends to produce better results than trying to split it word by word.
How newer models handle it
Newer Indian-language TTS models are trained specifically on conversational, code-switched data — the way people actually talk on calls, in voice notes, and in customer support chats. This lets them keep English loanwords (like "project," "meeting," "WhatsApp") sounding natural instead of forcing an artificial accent onto them.
What this means for you
If you're building or using a TTS tool for Indian audiences, plain English-only engines will fall short the moment Hindi enters the sentence. Tools like KairoVaani route Hindi-script text to an engine built for this exact problem, so mixed sentences come out sounding like a person actually speaking, not two separate voices stitched together.