PolyWhisper is an efficient multilingual Automatic Speech Recognition (ASR) system for Indian languages. It uses a frozen Whisper backbone with per-language LoRA adapters to achieve competitive accuracy at a fraction of the compute cost of full fine-tuning.
What is PolyWhisper?
PolyWhisper is a lightweight, production-ready ASR model for 5 major Indian languages: Hindi, Tamil, Telugu, Bengali, and Marathi. Unlike traditional approaches that fine-tune the entire model, PolyWhisper keeps the pretrained Whisper backbone frozen and trains small LoRA adapters (rank 16, ~14MB per language) that bolt onto the backbone at inference time.
1# Hindi2polywhisper transcribe audio.wav --lang hi
34# Tamil with JSON output5polywhisper transcribe audio.wav --lang ta --format json
67# Auto-detect language8polywhisper transcribe audio.wav
Python API
python
1from polywhisper import transcribe
23# Single file4result = transcribe("audio.wav", lang="hi")5print(result.text)# "नमस्ते, आप कैसे हैं?"6print(result.segments)# [Segment(text=..., start_sec=0.0, end_sec=5.2)]78# Long audio (auto-chunks into 30s segments)9result = transcribe("long_meeting.mp3", lang="te", max_new_tokens=512)
Batch Transcription
polywhisper batch ./audio_folder/ --lang ta --output results.json
SRT Subtitles
polywhisper transcribe video_audio.wav --lang hi --format srt > subtitles.srt
Supported Languages
Language
Code
Script
FLEURS WER
Status
Hindi
hi
Devanagari
37.2
Production-ready
Tamil
ta
Tamil
60.4
Production-ready
Telugu
te
Telugu
105.7
Retraining scheduled
Bengali
bn
Bengali
196.3
Retraining scheduled
Marathi
mr
Devanagari
167.3
Retraining scheduled
Hindi and Tamil achieve better results than full model fine-tuning (expert baseline) using only ~14MB adapters. Telugu, Bengali, and Marathi are being retrained with domain-matched data for significant improvements.
Performance Comparison
Model
Params
Hindi WER
Tamil WER
Telugu WER
Whisper-Base (vanilla)
74M
131.3
93.2
185.6
Whisper-Small (vanilla)
244M
62.3
68.8
129.6
Whisper-Medium (vanilla)
769M
35.4
49.1
110.3
PolyWhisper Expert (Base+LoRA)
74M+3.5M
38.6
74.2
91.9
PolyWhisper Product (Small+LoRA)
244M+3.5M
37.2
60.4
105.7
Lower WER is better. Evaluated on FLEURS test set with punctuation-normalized scoring.