Active Noise Reduction: Eliminating Cacophony

• Deepavali, the festival of lights, is a month and a half away, making loud noises a common issue.
• Active Noise Control (ANC) earphones or headphones can help protect against loud noises.
• ANC works by “destroying” unwanted noise from reaching the ears.
• The concept is based on destructive interference, where two sound waves meet each other, leading to three possibilities: constructive interference, destructive interference, or a mix of both.
• ANC technologies are designed to achieve destructive interference alone.
• A microphone picks up unwanted sound, generating an “antiphase” wave that destructively interferes with the sound.
• ANC built into individual headphones and earphones is cheaper than larger spaces requiring more power-intensive ANC.