Assertion: noise canceling microphone | /r/HasProperty | made since least 1935
Facets:
value: commercially
type: MANNER
Source sentences:
text: Commercially and militarily useful noise-canceling microphones have been made since at least 1935, Amelia Earhart used one on her 1935 flight from Hawaii to California and have been made since the 1940s by Roanwell, Electro-Voice and others.