 Tear down this wall!  was the challenge issued by United States President Ronald Reagan to Soviet Union leader Mikhail Gorbachev to destroy the Berlin Wall, in a speech at the Brandenburg Gate near the Berlin Wall on June 12, 1987, commemorating the 750th anniversary of Berlin.n the 1963  Ich bin ein Berliner  speech, U.S. President John F. Kennedy stated the support of the United States for democratic West Germany shortly after the Soviet-supported Communist state of East Germany erected the Berlin Wall as a barrier to prevent movement from East to West.
Feedback happens when a microphone picks up sound from speakers and then pipes that same sound back through the speakers and picks it up again. The never-ending loop of ear-pain is frustrating to experience, but fairly easy to fix by adjusting the levels of the speakers and microphone.
Your listening device or room recorder should always be silent and undetectable. If someone who is in the room where your voice recorder has been set up, you do not want them to hear a small click when the recording begins.If the listening device makes any noise or is perceptible, either because it looks like an unusual object in the room or because it looks like a bug, you are in trouble.hether you plan on using a listening device to eavesdrop, in the line of duty, or to observe nature, you will need to understand the different features available on room recorders and voice recorders. The average voice recorders will come with one of these two options, or both: voice activated and continuous recording.