IndicVoices-R: Unlocking a Massive Multilingual Multi-speaker Speech Corpus for Scaling Indian TTS

🎉 Accepted at NeurIPS 2025 (Datasets and Benchmark Track)

We present IndicVoices-R, an ASR enhanced TTS dataset for the 22 official Indian languages, with over 1700 hours of high-quality speech in the voice of more than 10k speakers. Follow the instructions given below to download and access the dataset.

We train the Voicecraft model, as implemented here to demonstrate the prowess of our dataset for Text-to-Speech.

Abstract

Recent advancements in text-to-speech (TTS) synthesis show that large-scale models trained with extensive web data produce highly natural-sounding output. However, such data is scarce for Indian languages due to the lack of high-quality, manually subtitled data on platforms like LibriVox or YouTube. To address this gap, we enhance existing large-scale ASR datasets containing natural conversations collected in low-quality environments to generate high-quality TTS training data. Our pipeline leverages the cross-lingual generalization of denoising and speech enhancement models trained on English and applied to Indian languages. This results in IndicVoices-R (IV-R), the largest multilingual Indian TTS dataset derived from an ASR dataset, with 1,704 hours of high-quality speech from 10,496 speakers across 22 Indian languages. IV-R matches the quality of gold-standard TTS datasets like LJSpeech, LibriTTS, and IndicTTS. We also introduce the IV-R Benchmark, the first to assess zero-shot, few-shot, and many-shot speaker generalization capabilities of TTS models on Indian voices, ensuring diversity in age, gender, and style. We demonstrate that fine-tuning an English pre-trained model on a combined dataset of high-quality IndicTTS and our IV-R dataset results in better zero-shot speaker generalization compared to fine-tuning on the IndicTTS dataset alone. Further, our evaluation reveals limited zero-shot generalization for Indian voices in TTS models trained on prior datasets, which we improve by fine-tuning the model on our data containing diverse set of speakers across language families. We open-source all data and code necessary to replicate the first TTS model for all 22 official Indian languages.

Manifest for Transcript and Metadata

We include the fields listed below in the manifest file for each language, accompanying the audios.

Field	Description
filename	Points to the wav file
text	Transcript for audio (normalized version)
duration	Audio duration in seconds
lang	ISO code for language (given in metadata)
samples	Number of samples
verbatim	Verbatim version of the transcript
normalized	Normalized version of the transcript (same as text)
speaker_id	Unique speaker ID
scenario	Type of data
task_name	Task name
gender	Gender of the speaker
age_group	Age group of the speaker
job_type	Job type of the speaker
qualification	Qualification of the speaker
area	Area from which the speaker belongs
district	District from which the speaker belongs
state	State from which the speaker belongs
occupation	Speaker's occupation
verification_report	Verification markers as given by the QA team
chunk_name	Audio chunk name
snr	Signal-to-noise ratio
c50	Clarity index (C50)
utterance_pitch_mean	Mean pitch of the utterance
utterance_pitch_std	Standard deviation of the utterance pitch
cer	Character error rate

Setup

Download the data

IndicVoices-R is available as tar files here To download and untar the dataset for a single language, use wget as follows:

wget -O <save as filename> <url to tar file> | tar -xz

Example

wget -O Assamese.tar https://indic-tts-public.objectstore.e2enetworks.net/data/ivr/Assamese.tar.gz | tar -xz

To download data for multiple languages, refer the data_links.txt file and run the following bash script

echo "Starting download and extraction process..."
while IFS= read -r url; do
    wget "$url" -O - | tar -xf -
done < data_links.txt
echo "Process completed."

or, download simultaneously

cat data_links.txt | xargs -n 1 -P 4 -I {} sh -c 'echo "Downloading and extracting: {}"; wget "{}" -O - | tar -xf -; echo "Completed: {}"'

Here -n 1 processes one url at a time and -P 4 runs 4 downloads in parallel - adjust according to your CPU resources.

Citation

If you used this repository or the dataset, please cite our work. Thank you :)

@article{sankar2024indicvoices,
  title={IndicVoices-R: Unlocking a Massive Multilingual Multi-speaker Speech Corpus for Scaling Indian TTS},
  author={Sankar, Ashwin and Anand, Srija and Varadhan, Praveen Srinivasa and Thomas, Sherry and Singal, Mehak and Kumar, Shridhar and Mehendale, Deovrat and Krishana, Aditi and Raju, Giri and Khapra, Mitesh},
  journal={arXiv preprint arXiv:2409.05356},
  year={2024}
}