It is hard to make a cellphone call from a noisy bar and pretend you’re calling from a quiet office. But Jaime Siegel of Woodcliff Lake, New Jersey has been working on it (US 2004/0192243).
His modified cellphone has two microphones; one on the front as usual and an identical one on the back face. When you make a call in a noisy place, both mics pick up much the same background noise, but the front mic picks up far more of your speech than the back mic. So the phone subtracts the back mic signal from the front…
