Added self references

sonogram.py

@@ -221,10 +221,10 @@ class Sonogram():
 
         return annotation, totalTimeInSeconds, waveform, sampleRate
 
-    def toDevice():
+    def toDevice(self):
         self.pipeline.to(self.device)
         print(f"Sonogram moved to {self.device}")
 
-    def toCPU():
+    def toCPU(self):
         self.pipeline.to('cpu')
         print(f"Sonogram moved to CPU")