diff --git a/utils.py b/utils.py
index a5c00bb..a9d1f38 100644
--- a/utils.py
+++ b/utils.py
@@ -1,17 +1,22 @@
 import torch
 import torchaudio
 import numpy as np
+from typing import List
 from itertools import repeat
 from collections import deque
 import torch.nn.functional as F
 
+
 torchaudio.set_audio_backend("soundfile")  # switch backend
 
-def validate(model, inputs):
+
+def validate(model,
+             inputs: torch.Tensor):
     with torch.no_grad():
         outs = model(inputs)
     return outs
 
+
 def read_audio(path: str,
                target_sr: int = 16000):
 
@@ -44,9 +49,14 @@ def init_jit_model(model_path: str,
     model.eval()
     return model
 
-def get_speech_ts(wav, model,
-                  trig_sum=0.25, neg_trig_sum=0.02,
-                  num_steps=8, batch_size=200, run_function=validate):
+
+def get_speech_ts(wav: torch.Tensor,
+                  model,
+                  trig_sum: float = 0.25,
+                  neg_trig_sum: float = 0.02,
+                  num_steps: int = 8,
+                  batch_size: int = 200,
+                  run_function=validate):
 
     num_samples = 4000
     assert num_samples % num_steps == 0
@@ -97,8 +107,9 @@ def get_speech_ts(wav, model,
 
 class VADiterator:
     def __init__(self,
-                 trig_sum=0.26, neg_trig_sum=0.02,
-                 num_steps=8):
+                 trig_sum: float = 0.26,
+                 neg_trig_sum: float = 0.02,
+                 num_steps: int = 8):
         self.num_samples = 4000
         self.num_steps = num_steps
         assert self.num_samples % num_steps == 0
@@ -126,19 +137,20 @@ class VADiterator:
         assert len(wav_chunk) <= self.num_samples
         self.num_frames += len(wav_chunk)
         if len(wav_chunk) < self.num_samples:
-            wav_chunk = F.pad(wav_chunk, (0, self.num_samples - len(wav_chunk)))  # assume that short chunk means end of audio
+            wav_chunk = F.pad(wav_chunk, (0, self.num_samples - len(wav_chunk)))  # short chunk => eof audio
             self.last = True
 
         stacked = torch.cat([self.prev, wav_chunk])
         self.prev = wav_chunk
 
-        overlap_chunks = [stacked[i:i+self.num_samples].unsqueeze(0) for i in range(self.step, self.num_samples+1, self.step)]  # 500 step is good enough
+        overlap_chunks = [stacked[i:i+self.num_samples].unsqueeze(0)
+                          for i in range(self.step, self.num_samples+1, self.step)]  # 500 sample step is good enough
         return torch.cat(overlap_chunks, dim=0)
 
     def state(self, model_out):
         current_speech = {}
         speech_probs = model_out[:, 1]  # this is very misleading
-        for i, predict in enumerate(speech_probs):  # add name
+        for i, predict in enumerate(speech_probs):
             self.buffer.append(predict)
             if (np.mean(self.buffer) >= self.trig_sum) and not self.triggered:
                 self.triggered = True
@@ -153,10 +165,14 @@ class VADiterator:
         return current_speech, self.current_name
 
 
-def state_generator(model, audios,
-                    onnx=False,
-                    trig_sum=0.26, neg_trig_sum=0.02,
-                    num_steps=8, audios_in_stream=5, run_function=validate):
+def state_generator(model,
+                    audios: List[str],
+                    onnx: bool = False,
+                    trig_sum: float = 0.26,
+                    neg_trig_sum: float = 0.02,
+                    num_steps: int = 8,
+                    audios_in_stream: int = 5,
+                    run_function=validate):
     VADiters = [VADiterator(trig_sum, neg_trig_sum, num_steps) for i in range(audios_in_stream)]
     for i, current_pieces in enumerate(stream_imitator(audios, audios_in_stream)):
         for_batch = [x.prepare_batch(*y) for x, y in zip(VADiters, current_pieces)]
@@ -173,7 +189,8 @@ def state_generator(model, audios,
         yield states
 
 
-def stream_imitator(audios, audios_in_stream):
+def stream_imitator(audios: List[str],
+                    audios_in_stream: int):
     audio_iter = iter(audios)
     iterators = []
     num_samples = 4000
@@ -207,8 +224,13 @@ def stream_imitator(audios, audios_in_stream):
         yield values
 
 
-def single_audio_stream(model, audio, onnx=False, trig_sum=0.26,
-                        neg_trig_sum=0.02, num_steps=8, run_function=validate):
+def single_audio_stream(model,
+                        audio: str,
+                        onnx: bool = False,
+                        trig_sum: float = 0.26,
+                        neg_trig_sum: float = 0.02,
+                        num_steps: int = 8,
+                        run_function=validate):
     num_samples = 4000
     VADiter = VADiterator(trig_sum, neg_trig_sum, num_steps)
     wav = read_audio(audio)