diff --git a/.gitignore b/.gitignore
index 756c107..80e61af 100644
--- a/.gitignore
+++ b/.gitignore
@@ -57,6 +57,26 @@ nosetests.xml
 coverage.xml
 *,cover
 
+# Claude settings
+.claude/*
+
+# Virtual environments
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# IDE files
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# Poetry
+# Do not ignore poetry.lock - it should be committed
+# poetry.lock is intentionally not ignored
+
 # Translations
 *.mo
 *.pot
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..9bd96de
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,89 @@
+[tool.poetry]
+name = "speechmetrics"
+version = "1.0.0"
+description = "A Python library for speech quality metrics"
+authors = ["Your Name <your.email@example.com>"]
+readme = "README.md"
+license = "MIT"
+packages = [{include = "speechmetrics"}]
+
+[tool.poetry.dependencies]
+python = "^3.9"
+numpy = "<1.24"
+scipy = "*"
+tqdm = "*"
+resampy = "*"
+pystoi = "*"
+museval = "*"
+tensorflow = ">=2.0.0"
+librosa = "*"
+pypesq = {git = "https://github.com/vBaiCai/python-pesq"}
+srmrpy = {git = "https://github.com/jfsantos/SRMRpy"}
+pesq = {git = "https://github.com/ludlows/python-pesq", develop = true}
+
+[tool.poetry.group.dev.dependencies]
+pytest = "^7.4.0"
+pytest-cov = "^4.1.0"
+pytest-mock = "^3.11.0"
+
+[tool.poetry.scripts]
+test = "pytest:main"
+tests = "pytest:main"
+
+[tool.pytest.ini_options]
+minversion = "6.0"
+addopts = [
+    "-ra",
+    "--strict-markers",
+    "--cov=speechmetrics",
+    "--cov-branch",
+    "--cov-report=term-missing:skip-covered",
+    "--cov-report=html",
+    "--cov-report=xml",
+    "--cov-fail-under=80",
+]
+testpaths = ["tests"]
+python_files = ["test_*.py", "*_test.py"]
+python_classes = ["Test*"]
+python_functions = ["test_*"]
+markers = [
+    "unit: marks tests as unit tests",
+    "integration: marks tests as integration tests",
+    "slow: marks tests as slow running",
+]
+
+[tool.coverage.run]
+source = ["speechmetrics"]
+branch = true
+omit = [
+    "*/tests/*",
+    "*/__init__.py",
+    "*/setup.py",
+]
+
+[tool.coverage.report]
+exclude_lines = [
+    "pragma: no cover",
+    "def __repr__",
+    "if self.debug:",
+    "if __name__ == .__main__.:",
+    "raise AssertionError",
+    "raise NotImplementedError",
+    "if 0:",
+    "if False:",
+    "class .*\\bProtocol\\):",
+    "@(abc\\.)?abstractmethod",
+]
+precision = 2
+show_missing = true
+skip_covered = false
+
+[tool.coverage.html]
+directory = "htmlcov"
+
+[tool.coverage.xml]
+output = "coverage.xml"
+
+[build-system]
+requires = ["poetry-core"]
+build-backend = "poetry.core.masonry.api"
\ No newline at end of file
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..a4dc38b
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,104 @@
+"""Shared pytest fixtures and configuration for speechmetrics tests."""
+
+import os
+import tempfile
+from pathlib import Path
+from typing import Generator
+
+import numpy as np
+import pytest
+
+
+@pytest.fixture
+def temp_dir() -> Generator[Path, None, None]:
+    """Create a temporary directory for test files."""
+    with tempfile.TemporaryDirectory() as tmp_dir:
+        yield Path(tmp_dir)
+
+
+@pytest.fixture
+def sample_audio_data() -> np.ndarray:
+    """Generate sample audio data for testing."""
+    sample_rate = 16000
+    duration = 1.0  # 1 second
+    frequency = 440.0  # A4 note
+    
+    t = np.linspace(0, duration, int(sample_rate * duration))
+    audio = np.sin(2 * np.pi * frequency * t)
+    
+    return audio
+
+
+@pytest.fixture
+def sample_rate() -> int:
+    """Standard sample rate for test audio."""
+    return 16000
+
+
+@pytest.fixture
+def mock_config() -> dict:
+    """Mock configuration dictionary for testing."""
+    return {
+        "model_path": "/path/to/model",
+        "batch_size": 32,
+        "num_workers": 4,
+        "device": "cpu",
+    }
+
+
+@pytest.fixture
+def test_data_dir() -> Path:
+    """Path to test data directory."""
+    return Path(__file__).parent / "data"
+
+
+@pytest.fixture
+def example_wav_file(temp_dir: Path, sample_audio_data: np.ndarray) -> Path:
+    """Create a temporary WAV file for testing."""
+    import scipy.io.wavfile as wavfile
+    
+    wav_path = temp_dir / "test_audio.wav"
+    wavfile.write(str(wav_path), 16000, (sample_audio_data * 32767).astype(np.int16))
+    
+    return wav_path
+
+
+@pytest.fixture(autouse=True)
+def reset_environment():
+    """Reset environment variables before each test."""
+    original_env = os.environ.copy()
+    yield
+    os.environ.clear()
+    os.environ.update(original_env)
+
+
+@pytest.fixture
+def mock_tensorflow(monkeypatch):
+    """Mock TensorFlow imports for faster testing."""
+    import sys
+    from unittest.mock import MagicMock
+    
+    mock_tf = MagicMock()
+    monkeypatch.setitem(sys.modules, "tensorflow", mock_tf)
+    
+    return mock_tf
+
+
+@pytest.fixture
+def noisy_audio_pair(sample_audio_data: np.ndarray) -> tuple[np.ndarray, np.ndarray]:
+    """Generate a clean and noisy audio pair for testing."""
+    clean = sample_audio_data
+    noise = np.random.normal(0, 0.1, size=clean.shape)
+    noisy = clean + noise
+    
+    return clean, noisy
+
+
+def pytest_configure(config):
+    """Configure pytest with custom settings."""
+    config.addinivalue_line(
+        "markers", "requires_model: mark test as requiring a pre-trained model"
+    )
+    config.addinivalue_line(
+        "markers", "requires_gpu: mark test as requiring GPU support"
+    )
\ No newline at end of file
diff --git a/tests/integration/__init__.py b/tests/integration/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/test_setup_validation.py b/tests/test_setup_validation.py
new file mode 100644
index 0000000..fb7f108
--- /dev/null
+++ b/tests/test_setup_validation.py
@@ -0,0 +1,71 @@
+"""Validation tests to ensure the testing infrastructure is properly set up."""
+
+import sys
+from pathlib import Path
+
+import numpy as np
+import pytest
+
+
+class TestSetupValidation:
+    """Test class to validate the testing infrastructure."""
+    
+    @pytest.mark.unit
+    def test_pytest_is_installed(self):
+        """Verify pytest is properly installed."""
+        assert "pytest" in sys.modules or True
+    
+    @pytest.mark.unit
+    def test_fixtures_are_available(self, temp_dir, sample_audio_data, sample_rate):
+        """Verify that custom fixtures are accessible."""
+        assert isinstance(temp_dir, Path)
+        assert temp_dir.exists()
+        
+        assert isinstance(sample_audio_data, np.ndarray)
+        assert len(sample_audio_data) == sample_rate
+        
+        assert isinstance(sample_rate, int)
+        assert sample_rate == 16000
+    
+    @pytest.mark.unit
+    def test_markers_are_configured(self, request):
+        """Verify custom markers are properly configured."""
+        markers = [marker.name for marker in request.node.iter_markers()]
+        assert "unit" in markers
+    
+    @pytest.mark.integration
+    def test_temp_file_creation(self, example_wav_file):
+        """Verify temporary file creation works."""
+        assert example_wav_file.exists()
+        assert example_wav_file.suffix == ".wav"
+    
+    @pytest.mark.unit
+    def test_coverage_is_enabled(self):
+        """Verify coverage reporting is enabled."""
+        try:
+            import coverage
+            assert coverage.__version__
+        except ImportError:
+            pytest.fail("Coverage module not installed")
+    
+    @pytest.mark.unit
+    @pytest.mark.slow
+    def test_multiple_markers(self, request):
+        """Test that multiple markers can be applied."""
+        markers = {marker.name for marker in request.node.iter_markers()}
+        assert "unit" in markers
+        assert "slow" in markers
+    
+    @pytest.mark.unit
+    def test_speechmetrics_importable(self):
+        """Verify the speechmetrics package can be imported."""
+        try:
+            import speechmetrics
+            assert speechmetrics
+        except ImportError:
+            pytest.skip("speechmetrics package not yet installed")
+    
+    @pytest.mark.parametrize("test_value", [1, 2, 3])
+    def test_parametrization_works(self, test_value):
+        """Verify pytest parametrization is functional."""
+        assert test_value in [1, 2, 3]
\ No newline at end of file
diff --git a/tests/unit/__init__.py b/tests/unit/__init__.py
new file mode 100644
index 0000000..e69de29