---
license: apache-2.0
language:
- en
tags:
- text-to-speech
- tts
- speech-synthesis
- pytorch
- tiny-tts
- experimental
pipeline_tag: text-to-speech
library_name: pytorch
---
# Inflect-Nano-v1
Inflect-Nano-v1 is an experimental ultra-small English TTS stack. It is built to test how far a sub-5M-parameter text-to-speech system can be pushed with a compact non-autoregressive acoustic model and a small neural vocoder.
This is **not** a production-quality or SOTA TTS model. It is a research/demo release: small, local, and runnable, but still audibly limited.
## Quick Facts
| Item | Value |
|---|---:|
| Total inference parameters | **4.632M** |
| Acoustic model | **3.465M** |
| Vocoder generator | **1.167M** |
| Language | English |
| Voice | single Mark-style synthetic male voice |
| Sample rate | 24 kHz |
| Acoustic output | 80-bin mel spectrogram |
| Vocoder | custom Snake-activation HiFi-GAN-style generator |
| Training source | synthetic Qwen3-TTS Mark-style teacher data |
## Audio Examples
These are unseen/OOD stress prompts, not hand-picked training rows.
| Prompt | Audio |
|---|---|
| Wait, are you actually being for real now? I can't believe it! | |
| Sophia sent me 43 pictures of her doing stuff... interesting. | |
| Please say chrysanthemum, thoroughly, proprietary, and rural without rushing through the middle syllables. | |
| No, seriously, did Jordan leave the receipt in Albuquerque, or did Priya move it to Worcester? | |
| The Wi-Fi password is Q7-Delta-9921, but please do not say the dash like a minus sign. | |
| I appreciate the honesty, but that explanation sounded weirdly dramatic for a Tuesday morning. | |
| Could you whisper the first part, then brighten up when you say, 'we finally solved it'? | |
| The dermatologist, the anesthesiologist, and the statistician all disagreed about February. | |
## Install
```bash
git clone https://huggingface.co/owensong/Inflect-Nano-v1
cd Inflect-Nano-v1
pip install -r requirements.txt
```
The text frontend uses TinyTTS-style English G2P and may download `bert-base-uncased` tokenizer files on first run.
## Usage
```bash
python inference.py \
--text "Wait, are you actually being for real now? I can't believe it!" \
--out sample.wav
```
CPU example:
```bash
python inference.py \
--device cpu \
--text "Please say chrysanthemum, thoroughly, proprietary, and rural clearly." \
--out sample_cpu.wav
```
Optional controls:
```bash
python inference.py \
--text "No, seriously, did Jordan leave the receipt in Albuquerque?" \
--length-scale 1.03 \
--pitch-scale 1.00 \
--energy-scale 1.00 \
--out sample_controlled.wav
```
Gradio demo:
```bash
python app.py
```
## Architecture
Inflect-Nano-v1 is a two-part TTS stack:
```text
text
-> TinyTTS-style normalization + G2P phoneme/tone/lang IDs
-> compact FastSpeech-style acoustic model
-> 80-bin mel spectrogram
-> Snake V2Mid HiFi-GAN-style vocoder
-> 24 kHz waveform
```
### Acoustic Model
The acoustic model is a small non-autoregressive FastSpeech-style network. It predicts duration, energy, brightness, and pitch, then expands token states into frame states and decodes mels.
Main config:
```json
{
"hidden": 168,
"encoder_layers": 5,
"decoder_layers": 6,
"decoder_ff_mult": 3,
"kernel_size": 7,
"speaker_dim": 64,
"dropout": 0.08,
"n_mels": 80,
"sample_rate": 24000,
"max_frames": 1400,
"postnet_scale": 0.1,
"use_frame_pitch": true,
"abs_frame_bins": 512
}
```
Acoustic parameter split:
```text
total acoustic: 3.465M
encoder: 1.292M
decoder: 1.211M
postnet: 0.276M
local context: 0.226M
frame GRU: 0.128M
heads/embeds/projections: remainder
```
### Vocoder
The vocoder is a custom Snake-activation HiFi-GAN-style generator.
Main config:
```json
{
"variant": "snake_v2mid",
"sample_rate": 24000,
"n_fft": 1024,
"hop_size": 256,
"win_size": 1024,
"num_mels": 80,
"fmax": 12000.0,
"upsample_rates": [8, 8, 2, 2],
"upsample_kernel_sizes": [16, 16, 4, 4],
"upsample_initial_channel": 144,
"resblock_kernel_sizes": [3, 7, 11],
"resblock_dilation_sizes": [[1, 3, 5], [1, 3, 5], [1, 3, 5]],
"activation": "snake"
}
```
The vocoder was trained with HiFi-GAN-style adversarial losses and multi-resolution spectral pressure. Discriminators are training-only and are not included in inference.
## Training Data
The final acoustic model was trained primarily on synthetic Mark-style teacher speech.
Known final broad training mix:
```text
mixed_80k_v2_40_v1_20_old_20
rows: 80,000
estimated duration: ~125.2 hours
composition:
40k newer generalization v2 examples
20k generalization v1 examples
20k older Mark anchor examples
```
The practical release voice is one speaker:
```text
qwen3_mark
```
## Training Recipe
The final F checkpoint is a staged recovery candidate, not a single monolithic run.
High-level acoustic lineage:
```text
1. Mark-focused acoustic base
2. mixed 80k generalization training
3. predictor-exposure heads training
4. robust prosody bridge
5. recovery phases A/B/C
6. short predictor-tail cleanup
```
Known acoustic continuation after the earlier Mark base:
```text
mixed80k broad training: ~32k selected checkpoint
predictor exposure: 9k steps
robust prosody bridge: 1.2k steps
recovery phase A: 3k steps
recovery phase B: 3k steps
recovery phase C: 2.5k steps
predictor tail: 0.8k steps
known continuation total: ~51.5k steps
```
Acoustic losses included mel reconstruction, MSE, delta/acceleration losses, duration loss, energy loss, brightness loss, pitch loss, predicted-prosody exposure, and robust-prosody exposure.
Final selected files in this repo:
```text
weights/inflect_nano_v1_acoustic.pt
weights/inflect_nano_v1_vocoder.pt
```
## Limitations
This model is intentionally tiny and has clear quality limits:
- Unseen text can stumble or sound unstable.
- The voice can sound robotic, buzzy, or artifacted.
- Long or unusual prompts are less reliable.
- It inherits habits from synthetic Qwen3-TTS teacher data.
- It is not a voice cloning model.
- It is not multilingual.
- It is not suitable for production accessibility, safety, or high-quality narration use.
## Recommended Framing
Use this as:
> An experimental 4.63M-parameter English TTS model exploring the quality/size tradeoff for ultra-small local speech synthesis.
Do not present it as SOTA or production-quality.
## License
Apache-2.0. The repo includes TinyTTS text frontend code; its license is included as `TINY_TTS_LICENSE`.