## Chart Type: NMSE vs. Frequency for Simulated List. Room
### Overview
The image presents a series of line graphs arranged in a 3x3 grid. Each graph displays the Normalized Mean Square Error (NMSE) in dB as a function of frequency for a simulated listening room. The rows represent different spatial perturbations applied to the listening room's location, while the columns represent different training conditions. Each graph contains multiple lines, each representing a different number of training samples (5, 15, 25, 35, 45, 55). The shaded regions around each line indicate uncertainty.
### Components/Axes
* **Title:** "Simulated List. Room" (with variations for spatial perturbation)
* **X-axis:** Frequency (Hz), with markers at approximately 30, 40, 50, 60, 70, 80, 90, 100, 200, and 300.
* **Y-axis:** NMSE (dB), with markers at 0, -5, -10, -15, -20, and -25.
* **Legend:** Located in the top-left graph, indicating the number of training samples:
* Blue: 5
* Green: 15
* Red: 25
* Yellow: 35
* Purple: 45
* Brown: 55
* **Spatial Perturbations (Rows):**
* Row 1: "Simulated List. Room"
* Row 2: "Simulated List. Room lx + U(-0.25, 0.25)m"
* Row 3: "Simulated List. Room lx + U(-1.0, 1.0)m"
* **Training Conditions (Columns):**
* Column 1: Training condition not explicitly stated on the graph, but implied to be the base condition.
* Column 2: "lx + U(-0.25, 0.25)m"
* Column 3: "lx + U(-1.0, 1.0)m"
* **Diagram Note:** In the top left of the image, there is a diagram with "Test ->" and "Train ↓" indicating the direction of testing and training.
### Detailed Analysis
**Row 1: Simulated List. Room**
* **Column 1:**
* Blue (5): Starts at approximately -23 dB at 30 Hz, rises sharply to about -12 dB at 50 Hz, fluctuates, and then gradually increases to about -5 dB at 300 Hz.
* Green (15): Starts at approximately -23 dB at 30 Hz, rises sharply to about -12 dB at 50 Hz, fluctuates, and then gradually increases to about -5 dB at 300 Hz.
* Red (25): Starts at approximately -23 dB at 30 Hz, rises sharply to about -12 dB at 50 Hz, fluctuates, and then gradually increases to about -5 dB at 300 Hz.
* Yellow (35): Starts at approximately -23 dB at 30 Hz, rises sharply to about -12 dB at 50 Hz, fluctuates, and then gradually increases to about -5 dB at 300 Hz.
* Purple (45): Starts at approximately -23 dB at 30 Hz, rises sharply to about -12 dB at 50 Hz, fluctuates, and then gradually increases to about -5 dB at 300 Hz.
* Brown (55): Starts at approximately -23 dB at 30 Hz, rises sharply to about -12 dB at 50 Hz, fluctuates, and then gradually increases to about -5 dB at 300 Hz.
* **Column 2:**
* Blue (5): Starts at approximately -23 dB at 30 Hz, rises sharply to about -10 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Green (15): Starts at approximately -23 dB at 30 Hz, rises sharply to about -10 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Red (25): Starts at approximately -23 dB at 30 Hz, rises sharply to about -10 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Yellow (35): Starts at approximately -23 dB at 30 Hz, rises sharply to about -10 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Purple (45): Starts at approximately -23 dB at 30 Hz, rises sharply to about -10 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Brown (55): Starts at approximately -23 dB at 30 Hz, rises sharply to about -10 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* **Column 3:**
* Blue (5): Starts at approximately -23 dB at 30 Hz, rises sharply to about -5 dB at 50 Hz, fluctuates, and then gradually increases to about -3 dB at 300 Hz.
* Green (15): Starts at approximately -23 dB at 30 Hz, rises sharply to about -5 dB at 50 Hz, fluctuates, and then gradually increases to about -3 dB at 300 Hz.
* Red (25): Starts at approximately -23 dB at 30 Hz, rises sharply to about -5 dB at 50 Hz, fluctuates, and then gradually increases to about -3 dB at 300 Hz.
* Yellow (35): Starts at approximately -23 dB at 30 Hz, rises sharply to about -5 dB at 50 Hz, fluctuates, and then gradually increases to about -3 dB at 300 Hz.
* Purple (45): Starts at approximately -23 dB at 30 Hz, rises sharply to about -5 dB at 50 Hz, fluctuates, and then gradually increases to about -3 dB at 300 Hz.
* Brown (55): Starts at approximately -23 dB at 30 Hz, rises sharply to about -5 dB at 50 Hz, fluctuates, and then gradually increases to about -3 dB at 300 Hz.
**Row 2: Simulated List. Room lx + U(-0.25, 0.25)m**
* **Column 1:**
* Blue (5): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Green (15): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Red (25): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Yellow (35): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Purple (45): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Brown (55): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* **Column 2:**
* Blue (5): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Green (15): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Red (25): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Yellow (35): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Purple (45): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Brown (55): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* **Column 3:**
* Blue (5): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Green (15): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Red (25): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Yellow (35): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Purple (45): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Brown (55): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
**Row 3: Simulated List. Room lx + U(-1.0, 1.0)m**
* **Column 1:**
* Blue (5): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Green (15): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Red (25): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Yellow (35): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Purple (45): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Brown (55): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* **Column 2:**
* Blue (5): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Green (15): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Red (25): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Yellow (35): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Purple (45): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Brown (55): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* **Column 3:**
* Blue (5): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Green (15): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Red (25): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Yellow (35): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Purple (45): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
* Brown (55): Starts at approximately -20 dB at 30 Hz, rises sharply to about -8 dB at 50 Hz, fluctuates, and then gradually increases to about -4 dB at 300 Hz.
### Key Observations
* The NMSE generally decreases (improves) as the frequency increases.
* Increasing the number of training samples (from 5 to 55) generally leads to a slight decrease in NMSE, but the effect is not dramatic. The lines are very close together.
* The spatial perturbation "lx + U(-1.0, 1.0)m" generally results in a slightly lower NMSE compared to "lx + U(-0.25, 0.25)m" and the base "Simulated List. Room" condition.
* There are noticeable fluctuations in NMSE across the frequency range, indicating resonances or other acoustic phenomena within the simulated room.
### Interpretation
The data suggests that increasing the number of training samples has a limited impact on the NMSE for this particular simulated listening room scenario. The spatial perturbation of the listening room's location appears to have a more significant effect, with larger perturbations (U(-1.0, 1.0)m) leading to slightly better performance. The fluctuations in NMSE across the frequency range highlight the importance of considering the acoustic characteristics of the room when evaluating the performance of a system. The "Test ->" and "Train ↓" diagram suggests that the training and testing data are generated using different methods or conditions, which could explain the need for spatial perturbation to improve generalization. The U(-0.25, 0.25)m and U(-1.0, 1.0)m likely represent a uniform distribution of spatial offsets.