diff --git a/src/cryo_sbi/wpa_simulator/cryo_em_simulator.py b/src/cryo_sbi/wpa_simulator/cryo_em_simulator.py
index d2bdd32..b097a1e 100644
--- a/src/cryo_sbi/wpa_simulator/cryo_em_simulator.py
+++ b/src/cryo_sbi/wpa_simulator/cryo_em_simulator.py
@@ -25,8 +25,9 @@ def cryo_em_simulator(
     snr,
     num_pixels,
     pixel_size,
-    noise=True,
     ctf=True,
+    noise=True,
+    normalize=True,
     ):
     """
     Simulates a bacth of cryo-electron microscopy (cryo-EM) images of a set of given coars-grained models.
@@ -60,7 +61,8 @@ def cryo_em_simulator(
         image = apply_ctf(image, defocus, b_factor, amp, pixel_size)
     if noise:
         image = add_noise(image, snr)
-    image = gaussian_normalize_image(image)
+    if normalize:
+        image = gaussian_normalize_image(image)
     return image
 
 
@@ -148,7 +150,7 @@ def max_index(self) -> int:
             int: Maximum index of the model file.
         """
         return len(self._models) - 1
-
+    
     def simulate(self, num_sim, indices=None, return_parameters=False, batch_size=None, noise=True, ctf=True):
         """
         Simulate cryo-EM images using the specified models and prior distributions.
@@ -201,34 +203,73 @@ def simulate(self, num_sim, indices=None, return_parameters=False, batch_size=No
             return images.cpu(), parameters
         else:
             return images.cpu()
+        
+
+    def simulate_with_micrograph_noise(self, num_sim, micrographs, indices=None, return_parameters=False, parameters=None, batch_size=None, ctf=True, snr=0.0001):
+        """
+        Simulate cryo-EM images using the specified models and prior distributions.
+
+        Args:
+            num_sim (int): The number of images to simulate.
+            indices (torch.Tensor, optional): The indices of the images to simulate. If None, all images are simulated.
+            return_parameters (bool, optional): Whether to return the sampled parameters used for simulation.
+            batch_size (int, optional): The batch size to use for simulation. If None, all images are simulated in a single batch.
 
-    def simulate_with_micrograph_noise(self, num_sim, micrographs, indices=None, return_parameters=False, batch_size=None, ctf=True, snr=0.0001):
-            self._init_micrograph_loader(micrographs, self._config["N_PIXELS"], num_noise_samples=num_sim)
-            images_and_maybe_params = self.simulate(
-                num_sim=num_sim,
-                indices=indices,
-                return_parameters=return_parameters,
-                batch_size=batch_size,
+        Returns:
+            torch.Tensor or tuple: The simulated images as a tensor of shape (num_sim, num_pixels, num_pixels),
+            and optionally the sampled parameters as a tuple of tensors.
+        """
+        if parameters is None:
+            parameters = self._priors.sample((num_sim,))
+        
+        indices = parameters[0] if indices is None else indices
+        if indices is not None:
+            assert isinstance(
+                indices, torch.Tensor
+            ), "Indices are not a torch.tensor, converting to torch.tensor."
+            assert (
+                indices.dtype == torch.float32
+            ), "Indices are not a torch.float32, converting to torch.float32."
+            assert (
+                indices.ndim == 2
+            ), "Indices are not a 2D tensor, converting to 2D tensor. With shape (batch_size, 1)."
+            parameters[0] = indices
+
+        images = []
+        if batch_size is None:
+            batch_size = num_sim
+
+        self._init_micrograph_loader(micrographs, self._config["N_PIXELS"], num_noise_samples=batch_size)
+
+        for i in range(0, num_sim, batch_size):
+            batch_indices = indices[i : i + batch_size]
+            batch_parameters = [param[i : i + batch_size] for param in parameters[1:]]
+            batch_images = cryo_em_simulator(
+                self._models,
+                batch_indices,
+                *batch_parameters,
+                self._num_pixels,
+                self._pixel_size,
                 noise=False,
-                ctf=ctf
+                ctf=ctf,
+                normalize=False
             )
-            if return_parameters:
-                images, parameters = images_and_maybe_params
-            else:
-                images = images_and_maybe_params
-            print("finished simulating images, drawing noise samples...")
+            noise_power = get_snr(batch_images, batch_parameters[-1])
+            
             noise_samples = []
             for noise_sample in self._micrograph_loader:
                 noise_samples.append(noise_sample)
-            noise_samples = torch.cat(noise_samples, dim=0)
-
-            print("finished drawing noise samples, adding noise to images...")
-            noise_samples = noise_samples / snr
+            noise_samples = torch.cat(noise_samples, dim=0).to(self._device)
+            noise_samples = noise_samples * noise_power
+            batch_images = batch_images + noise_samples
+            batch_images = gaussian_normalize_image(batch_images)
 
-            images = images + noise_samples
-            images = gaussian_normalize_image(images)
+            images.append(batch_images.cpu())
 
+        images = torch.cat(images, dim=0)
 
-            return images
-        
+        if return_parameters:
+            return images.cpu(), parameters
+        else:
+            return images.cpu()