diff --git a/process b/process
index dabdc51..3eddca1 100755
--- a/process
+++ b/process
@@ -18,8 +18,8 @@ DETECT_FREQUENCY_TOLERANCE = 2 # Hz
 DETECT_FREQUENCY_FROM = DETECT_FREQUENCY - DETECT_FREQUENCY_TOLERANCE # Hz
 DETECT_FREQUENCY_TO = DETECT_FREQUENCY + DETECT_FREQUENCY_TOLERANCE # Hz
 ADJACENCY_FACTOR = 2 # area to look for noise around the target frequency
-AMPLITUDE_THRESHOLD = 200 # rDB
-BLOCK_SECONDS = 1 # seconds
+AMPLITUDE_THRESHOLD = 200 # relative DB (rDB) (because not calibrated)
+BLOCK_SECONDS = 3 # seconds (longer means more frequency resolution, but less time resolution)
 
 
 def process_recording(filename):
@@ -51,13 +51,17 @@ def process_recording(filename):
         max_amplitude_index = np.argmax(adjacent_amplitudes)
         max_freq = adjacent_labels[max_amplitude_index]
 
+        # get the average amplitude of the adjacent frequencies
+        noise = np.mean(adjacent_amplitudes)/max_amplitude
+
         # check for detection criteria
         max_freq_detected = DETECT_FREQUENCY_FROM <= max_freq <= DETECT_FREQUENCY_TO
         amplitude_detected = max_amplitude > AMPLITUDE_THRESHOLD
+        low_noise_detected = noise < 0.1
 
         # conclude detection
-        if max_freq_detected and amplitude_detected:
-            print(f'{block_date}: {max_amplitude:.2f}rDB @ {max_freq:.2f}Hz')
+        if max_freq_detected and amplitude_detected and low_noise_detected:
+            print(f'{block_date}: {max_amplitude:.1f}rDB @ {max_freq:.1f}Hz ({noise:.3f}rDB noise)')