## Line Graph: Noise Robustness @ 1.5 kbps
### Overview
The graph illustrates the relative Word Error Rate (WER) increase under varying noise levels (Signal-to-Noise Ratio, SNR) for three systems: Baseline, Baseline + HuBERT, and Baseline + Whisper. The y-axis represents the percentage increase in WER, while the x-axis shows SNR levels from "Clean" (no noise) to 0dB (highest noise). A shaded area highlights the "Robustness Gain" between Baseline and Whisper.
### Components/Axes
- **X-axis (Noise Level/SNR)**: Labeled "Noise Level (SNR)" with categories: Clean, 20dB, 10dB, 5dB, 0dB.
- **Y-axis (Relative WER Increase)**: Labeled "Relative WER Increase (%)" with a scale from 0 to 60.
- **Legend**: Located in the bottom-right corner, with three entries:
- **Baseline**: Gray circles (○).
- **+ HuBERT**: Blue squares (■).
- **+ Whisper**: Red triangles (▲).
- **Shaded Area**: A pink region between Baseline and Whisper lines, labeled "Robustness Gain" with an arrow pointing to the 5dB mark.
### Detailed Analysis
1. **Baseline (Gray ○)**:
- Clean: 0% WER increase.
- 20dB: ~15% increase.
- 10dB: ~37% increase.
- 5dB: ~49% increase.
- 0dB: ~50% increase.
- **Trend**: Steep upward slope as SNR decreases.
2. **+ HuBERT (Blue ■)**:
- Clean: 0% WER increase.
- 20dB: ~12% increase.
- 10dB: ~28% increase.
- 5dB: ~40% increase.
- 0dB: ~48% increase.
- **Trend**: Less steep than Baseline, showing moderate improvement.
3. **+ Whisper (Red ▲)**:
- Clean: 0% WER increase.
- 20dB: ~11% increase.
- 10dB: ~29% increase.
- 5dB: ~40% increase.
- 0dB: ~48% increase.
- **Trend**: Similar to HuBERT but slightly lower WER increases at 20dB and 10dB.
4. **Shaded Area (Robustness Gain)**:
- Visible between Baseline and Whisper lines, indicating Whisper reduces WER compared to Baseline.
- Largest gain observed at 5dB (Baseline: 49% vs. Whisper: 40%).
### Key Observations
- **Noise Sensitivity**: All systems show increased WER as SNR decreases, with Baseline being the most affected.
- **Robustness Gain**: Whisper consistently outperforms Baseline, with the largest relative improvement at lower SNR levels (e.g., 5dB).
- **HuBERT vs. Whisper**: HuBERT and Whisper perform similarly at 5dB and 0dB but Whisper has a slight edge at 20dB and 10dB.
### Interpretation
The graph demonstrates that adding Whisper to the Baseline system significantly improves noise robustness, reducing WER increases by up to 9% at 5dB SNR. HuBERT also enhances robustness but to a lesser extent. The shaded "Robustness Gain" area visually emphasizes Whisper's effectiveness in noisy conditions, suggesting it is a critical component for maintaining accuracy in low-SNR environments. The convergence of HuBERT and Whisper lines at 0dB implies diminishing returns at extreme noise levels, where both struggle to mitigate errors.
