Update README.md
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README.md
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@@ -12,3 +12,305 @@ short_description: Audio classification with Mel-spectrogram CNNs.
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Check out the configuration reference at https://huggingface.co/docs/hub/spaces-config-reference
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---
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Check out the configuration reference at https://huggingface.co/docs/hub/spaces-config-reference
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---
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# Audio-Classification-Raw-Audio-to-Mel-Spectrogram-CNNs
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Complete end-to-end audio classification pipeline using deep learning. From raw recordings to Mel spectrogram CNNs, includes preprocessing, augmentation, dataset validation, model training, and evaluation — a reproducible blueprint for speech, environmental, or general sound classification tasks.
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---
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# Audio Classification Pipeline — From Raw Audio to Mel-Spectrogram CNNs
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> *“In machine learning, the model is rarely the problem — the data almost always is.”*
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> — A reminder I kept repeating to myself while building this project.
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This repository contains a complete, professional, end-to-end pipeline for **audio classification using deep learning**, starting from **raw, messy audio recordings** and ending with a fully trained **CNN model** using **Mel spectrograms**.
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The workflow includes:
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* Raw audio loading
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* Cleaning & normalization
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* Silence trimming
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* Noise reduction
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* Chunking
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* Data augmentation
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* Mel spectrogram generation
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* Dataset validation
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* CNN training
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* Evaluation & metrics
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It is a fully reproducible blueprint for real-world audio classification tasks.
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---
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# Project Structure
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Here is a quick table summarizing the core stages of the pipeline:
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| Stage | Description | Output |
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| ----------------------- | -------------------------------------- | ---------------- |
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| **1. Raw Audio** | Unprocessed WAV/MP3 files | Audio dataset |
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| **2. Preprocessing** | Trimming, cleaning, resampling | Cleaned signals |
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| **3. Augmentation** | Pitch shift, time stretch, noise | Expanded dataset |
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| **4. Mel Spectrograms** | Converts audio → images | PNG/IMG files |
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| **5. CNN Training** | Deep model learns spectrogram patterns | `.h5` model |
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| **6. Evaluation** | Accuracy, F1, Confusion Matrix | Metrics + plots |
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---
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# 1. Loading & Inspecting Raw Audio
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The dataset is loaded from directory structure:
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```python
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paths = [(path.parts[-2], path.name, str(path))
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for path in Path(extract_to).rglob('*.*')
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if path.suffix.lower() in audio_extensions]
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df = pd.DataFrame(paths, columns=['class', 'filename', 'full_path'])
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df = df.sort_values('class').reset_index(drop=True)
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```
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During EDA, I computed:
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* Duration
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* Sample rate
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* Peak amplitude
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And visualized duration distribution:
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```python
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plt.hist(df['duration'], bins=30, edgecolor='black')
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plt.xlabel("Duration (seconds)")
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plt.ylabel("Number of recordings")
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plt.title("Audio Duration Distribution")
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plt.show()
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```
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---
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# 2. Audio Cleaning & Normalization
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Bad samples were removed, silent files filtered, and amplitudes normalized:
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```python
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peak = np.abs(y).max()
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if peak > 0:
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y = y / peak * 0.99
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```
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This ensures consistency and prevents the model from learning from corrupted audio.
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---
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# 3. Advanced Preprocessing
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Preprocessing included:
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* Silence trimming
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* Noise reduction
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* Resampling → **16 kHz**
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* Mono conversion
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* 5-second chunking
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```python
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TARGET_DURATION = 5.0
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TARGET_SR = 16000
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TARGET_LENGTH = int(TARGET_DURATION * TARGET_SR)
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```
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Every audio file becomes a clean, consistent chunk ready for feature extraction.
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---
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# 4. Audio Augmentation
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To improve generalization, I applied augmentations:
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```python
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augment = Compose([
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Shift(min_shift=-0.3, max_shift=0.3, p=0.5),
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PitchShift(min_semitones=-2, max_semitones=2, p=0.5),
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TimeStretch(min_rate=0.8, max_rate=1.25, p=0.5),
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AddGaussianNoise(min_amplitude=0.001, max_amplitude=0.015, p=0.5)
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])
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```
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Every augmented file receives a unique name to avoid collisions.
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---
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# 5. Mel Spectrogram Generation
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Each cleaned audio chunk is transformed into a **Mel spectrogram**:
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```python
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S = librosa.feature.melspectrogram(
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y=y, sr=SR,
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n_fft=N_FFT,
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hop_length=HOP_LENGTH,
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n_mels=N_MELS
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)
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S_dB = librosa.power_to_db(S, ref=np.max)
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```
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* Output: **128×128 PNG images**
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* Separate directories per class
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* Supports both original & augmented samples
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These images become the CNN input.
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### ***Example of Mel Spectrogram Images***
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.png?generation=1763570855911665&alt=media)
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---
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# 6. Dataset Validation
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After spectrogram creation:
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* Corrupted images removed
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* Duplicate hashes filtered
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* Filename integrity checked
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* Class folders validated
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```python
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df['file_hash'] = df['full_path'].apply(get_hash)
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duplicate_hashes = df[df.duplicated(subset=['file_hash'], keep=False)]
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```
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This step ensures **clean, reliable** training data.
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---
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# 7. Building TensorFlow Datasets
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The dataset is built with batching, caching, prefetching:
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```python
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train_ds = tf.data.Dataset.from_tensor_slices((train_paths, train_labels))
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train_ds = train_ds.map(load_and_preprocess, num_parallel_calls=AUTOTUNE)
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train_ds = train_ds.shuffle(1024).batch(batch_size).prefetch(AUTOTUNE)
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```
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I used a simple image-level augmentation pipeline:
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```python
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data_augmentation = tf.keras.Sequential([
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tf.keras.layers.InputLayer(input_shape=(231, 232, 4)),
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tf.keras.layers.RandomFlip("horizontal"),
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tf.keras.layers.RandomRotation(0.1),
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tf.keras.layers.RandomZoom(0.1),
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])
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```
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---
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# 8. CNN Architecture
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The CNN captures deep frequency-time patterns across Mel images.
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Key features:
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* Multiple Conv2D + BatchNorm blocks
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* Dropout
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* L2 regularization
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* Softmax output
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```python
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model = Sequential([
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data_augmentation,
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Conv2D(32, (3,3), padding='same', activation='relu', kernel_regularizer=l2(weight_decay)),
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BatchNormalization(),
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MaxPooling2D((2,2)),
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Dropout(0.2),
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# ... more layers ...
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Flatten(),
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Dense(num_classes, activation='softmax')
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])
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```
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---
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# 9. Training Strategy
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```python
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reduce_lr = ReduceLROnPlateau(monitor='val_loss', factor=0.5, patience=10)
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early_stopping = EarlyStopping(monitor='val_loss', patience=40, restore_best_weights=True)
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history = model.fit(
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train_ds,
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validation_data=val_ds,
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epochs=50,
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callbacks=[reduce_lr, early_stopping]
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)
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```
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The model converges smoothly while avoiding overfitting.
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---
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# 10. Evaluation
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Performance is evaluated using:
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* Accuracy
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* Precision, recall, F1-score
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* Confusion matrix
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* ROC/AUC curves
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```python
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y_pred = np.argmax(model.predict(test_ds), axis=1)
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print(classification_report(y_true, y_pred, target_names=le.classes_))
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```
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Confusion matrix:
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```python
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sns.heatmap(confusion_matrix(y_true, y_pred), annot=True, cmap='Blues')
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plt.title("Confusion Matrix")
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plt.show()
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```
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---
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# 11. Saving the Model & Dataset
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```python
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model.save("Audio_Model_Classification.h5")
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shutil.make_archive("/content/spectrograms", 'zip', "/content/spectrograms")
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```
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The entire spectrogram dataset is also zipped for sharing or deployment.
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---
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# Final Notes
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This project demonstrates:
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* How to clean & prepare raw audio at a professional level
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* Audio augmentation best practices
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* How Mel spectrograms unlock CNN performance
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* A full TensorFlow training pipeline
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* Proper evaluation, reporting, and dataset integrity
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If you're working on sound recognition, speech tasks, or environmental audio detection, this pipeline gives you a **complete production-grade foundation**.
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---
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# **Results**
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> **Note:** Click the image below to view the video showcasing the project’s results.
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<a href="https://files.catbox.moe/suzziy.mp4">
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<img src="https://images.unsplash.com/photo-1611162616475-46b635cb6868?q=80&w=1974&auto=format&fit=crop&ixlib=rb-4.1.0&ixid=M3wxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8fA%3D%3D" width="400">
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</a>
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<hr style="border-bottom: 5px solid gray; margin-top: 10px;">
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> **Note:** If the video above is not working, you can access it directly via the link below.
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[Watch Demo Video](Results/Spectrogram_CNN_Audio_Classification.mp4)
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