Antinoise systems — noise cancellation, Electrical Engineering

Assignment Help:

Q. Antinoise Systems — Noise Cancellation?

Traditionally sound-absorbing materials have been used quite effectively to reduce noise levels in aircraft, amphitheaters, and other locations. An alternate way is to develop an electronic system that cancels the noise. Ear doctors and engineers have successfully developed ear devices that will nearly eliminate the bothersome and irritating noise (so-called tinnitus) experienced by patients suffering from M´ eni` ere's disease. For passengers in airplanes, helicopters, and other flying equipment, a proper headgear is being developed in order to eliminate the annoying noise.

Applications could conceivably extend to people residing near airports and bothered by airplane takeoffs and landings. For industrial workers who are likely to develop long-term ill effects due to various noises they may be subjected to in their workplace, and even for persons who are irritated by the pedestrian noise levels in certain locations, antinoise systems that nearly eliminate or nullify noise become very desirable.

963_Antinoise Systems — Noise Cancellation.png

Figure illustrates in block-diagram form the principle of noise cancellation as applied to an aircraft carrying passengers. The electric signal resulting after sampling the noise at the noise sources is passed through a filter whose transfer function is continuously adjusted by a special-purpose computer to match the transfer function of the sound path. An inverted version of the signal is finally applied to loudspeakers, which project the sound waves out of phase with those from the noise sources, nearly canceling the noise. Microphones on the headrests monitor the sound experienced by the airline passengers so that the computer can determine the proper filter adjustments.

Signal processing, which is concerned with manipulating signals to extract information and to use that information to generate other useful electric signals, is indeed an important and farreaching subject.


Related Discussions:- Antinoise systems — noise cancellation

Components in a microprocessor, What are the basic components in a Micropro...

What are the basic components in a Microprocessor? 1) Address lines to refer to the address of a block 2) Data lines for data transmit 3) IC chips 4 processing data

Obtain the complete solution for the voltage, Consider the circuit of Figur...

Consider the circuit of Figure and obtain the complete solution for the voltage v C (t) across the 5-F capacitor and the voltage vx(t) across the 5- resistor.

Clampers, what would the change after adding a registor paralelly in clampe...

what would the change after adding a registor paralelly in clampers?

Merits and demerits of stepper motor - stepper motor , Merits and Demerits ...

Merits and Demerits of Stepper Motor Followings  are the  merits and demerits  of stepper motors. Merits : a.They are compatible  with digital systems b.For the co

What is the advantage of using jfet as an amplifier, Q. What is the advanta...

Q. What is the advantage of using JFET as an amplifier? As an amplifier of small time-varying signals, the JFET has a number of valuable assets. First of all it has a very high

Instruction set architecture, assume that the top of the stack in the progr...

assume that the top of the stack in the program is pointed by the register sp.

Solid-state control of synchronous motors, Solid-State Control of Synchrono...

Solid-State Control of Synchronous Motors  The speed of a synchronous motor can be controlled by changing its supply frequency. With variable-frequency control, two modes of op

Find the source voltage, Q. A semiconductor diode with IS = 10µA and a 1-k...

Q. A semiconductor diode with IS = 10µA and a 1-k resistor in series is forward-biased with a voltage source to yield a current of 30mA. Find the source voltage if the diode I-V e

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd