diff --git a/dnd_transcribe/argparse.py b/dnd_transcribe/argparse.py
index babe7cd..81133b1 100644
--- a/dnd_transcribe/argparse.py
+++ b/dnd_transcribe/argparse.py
@@ -19,6 +19,12 @@ def build_argument_parser() -> argparse.ArgumentParser:
         action="store_false",
         help="Disable using the GPU with CUDA",
     )
+    parser.add_argument(
+        "--block-len",
+        type=int,
+        default=30,
+        help="Block length in seconds of audio sent when streaming or to whisper",
+    )
     parser.add_argument(
         "-m",
         "--model",
diff --git a/dnd_transcribe/inference.py b/dnd_transcribe/inference.py
index 4ffe5cf..6691e3d 100644
--- a/dnd_transcribe/inference.py
+++ b/dnd_transcribe/inference.py
@@ -25,8 +25,11 @@ class InferredTranscript(typing.NamedTuple):
 
 
 class Inference:
-    def __init__(self, model_name: str, use_gpu: bool = True) -> None:
+    def __init__(
+        self, model_name: str, block_len: int = 20, use_gpu: bool = True
+    ) -> None:
         self.model_name = model_name
+        self.block_len = block_len
         cuda_available = use_gpu and torch.cuda.is_available()
         self.device = "cuda" if cuda_available else "cpu"
         self.torch_dtype = torch.float16 if cuda_available else torch.float32
@@ -52,7 +55,7 @@ class Inference:
             raise Exception(f"Unsupported sample rate {samplerate}")
         stream = librosa.stream(
             audio_file_path,
-            block_length=20,
+            block_length=self.block_len,
             frame_length=AUDIO_SAMPLE_RATE,
             hop_length=AUDIO_SAMPLE_RATE,
         )
@@ -126,7 +129,7 @@ class Inference:
             model=self.model,
             tokenizer=self.processor.tokenizer,
             feature_extractor=self.processor.feature_extractor,
-            chunk_length_s=30,
+            chunk_length_s=self.block_len,
             batch_size=16,  # batch size for inference - set based on your device
             torch_dtype=self.torch_dtype,
             device=self.device,
diff --git a/dnd_transcribe/main.py b/dnd_transcribe/main.py
index 3d1f471..56d2081 100644
--- a/dnd_transcribe/main.py
+++ b/dnd_transcribe/main.py
@@ -13,7 +13,11 @@ def main():
         logging.basicConfig(level=logging.ERROR, format=logging_format)
     else:
         logging.basicConfig(level=logging.INFO, format=logging_format)
-    inference = dnd_transcribe.inference.Inference(args.model, use_gpu=args.use_gpu)
+    inference = dnd_transcribe.inference.Inference(
+        args.model,
+        block_len=args.block_len,
+        use_gpu=args.use_gpu,
+    )
     if args.audio_file is not None:
         _print_inferred_transcript(inference.file_to_text(args.audio_file))
     elif args.stream_audio_file is not None: