As an engineering student or engineer, you know that electronic systems are everywhere, from your phone to your car to the appliances in your home.
But you might not know that these systems have a hidden enemy that can affect how well they work and how reliable they are: background noise.
Background noise, like the hum of electrical wires or the interference from other devices, can hurt the quality of signals and make it hard for electronic systems to work.
Because of this, it is important to know a lot about background noise and how to get rid of it effectively.
In this blog post, we will learn about background noise, including where it comes from, what it does, and how to stop it from messing up electronics.
Understanding Background Noise in Electronic Systems
Formal definition:
The undesired signals that are always present in an electronic or other system, independent of whether or not the undesirable signal is present.
Background noise is any energy that is unwanted or bothersome and gets in the way of a communication signal. It can come from natural things like wind, rain, snow, temperature, humidity, and the moon's gravitational pull.
It can also come from things that people have made, like electronic systems, power spectral density, magnetic fields, transmission lines, generators, power plants, computers, or cell phones.
Background noise affects the quality of signals in electronic systems by making it harder for people to communicate.
Noise is an error or random disturbance of a useful information signal in a communication channel that is not wanted.
S/N or SNR stands for signal-to-noise ratio.
The signal-to-noise ratio (S/N or SNR) is a way to compare the strength of a wanted signal to the strength of background noise. When it comes to network services, a higher S/N ratio is better than a lower one.
If the S/N ratio of Wi-Fi signals is too low, for example, it can hurt the performance of the network because it makes it harder for devices to tell the signal they want from the noise.
This can cause packets to be dropped and data to be sent over and over again, lowering throughput and increasing latency.
How shielding and grounding help cut down on background noise
Shielding and grounding can help reduce background noise in electronic systems by giving all devices a single point of ground, preventing ground loops, increasing the distance between the aggressor and victim nets, using shielded cables, and setting up a proper grounding system.Shielded cables can be used to keep electrostatic noise from getting into the conductors and to keep electrostatic noise inside the shield. Using shielded cables in the right way will help cut down on electrostatic noise that comes from common mode.
For the DAQ system to have less noise problems, grounding and ground bonding must be done during the design and installation phases.
By following these best practices, you can reduce the amount of signal noise that affects process control networks and make sure electronic systems are working properly.
Shielding can help reduce electromagnetic interference (EMI) and radio-frequency interference (RFI) by putting a conductive barrier between the device and the source of interference.
Unlocking the Power of Background Noise: From Nuisance to Creative Tool
Still hard to understand? Let me change the point of view a bit:
Are you sick of having crystal-clear sound and easy connections on your devices? Do you want to make your electronic systems harder and more frustrating to use? Well, all you have to do is listen to the background noise! Yes, that is right.
You can turn a perfectly working system into a chaotic mess by letting the unwanted signals that are always present in electronic systems run amok.
Do not believe us? Just sit back, take it easy, and let the noise in the background do its thing!
Okay, that was just a joke made to look like a TV ad.
Now let's go back to the explanation...
Measuring and Quantifying Background Noise
Background noise can affect electronic systems.
This can lower the quality of signals and affect how well a network works.
It is important to measure and count background noise so that you can better understand how it affects you and come up with ways to get rid of it.
Methods for Measuring Background Noise
In electronic systems, there are several ways to measure and count background noise.
A noise source that sends a known noise signal into the circuit of interest is one way to do this.
This makes it possible to measure how much random noise there is in a circuit.
The noise factor is also used in the gain method, which is another way to measure background noise in a circuit.
The noise figure of a circuit is measured by the gain method.
The noise figure is a measure of how much noise the circuit adds to the signal it is given.
A spectrum analyzer can also measure the amount of noise power at the output.
This device measures a signal's power spectrum and can be used to find noise sources and figure out how loud they are.
Units of Measurement for Electrical Noise Levels
Electrical noise level measurement units include electrical power N in watts or dBm, root mean square (RMS) voltage in volts, dBV, and mean squared error (MSE) in volts squared.
Sound Level Meters
Sound level meters are tools that measure the amount of noise in decibels (dB).
These devices have a setting called A-weighting that changes the readings to match the way the human ear responds to different frequencies.
Sound level meters are often used to measure how loud the environment is, and they are an important tool for setting rules and regulations about noise.
Signal-to-Noise Ratio (S/N)
Signal-to-noise ratio (S/N) is a way to compare the strength of a wanted signal to the strength of noise in the background.
S/N is usually measured in decibels, and a base-10 logarithm can be used to figure it out.
For example, if you measure in microvolts, you can use this formula: S/N = 20 log10(Ps/Pn), where Ps is the power of the signal and Pn is the power of the noise in the background.
Sources of Background Noise in Electronic Systems and How to Minimize or Eliminate Them
Noise can come from both inside and outside of electronic systems. Noise that comes from inside the amplifier is called internal noise. Noise that comes from outside the system is called external noise.
Conductive noise, which comes into the system through cables, and radiated noise, which comes from somewhere else through the air or vacuum, are both types of external noise.
Electronic circuitry in devices that is not well-made and does not block enough noise from both inside and outside will also be more susceptible to signal noise.
Filtering and Grounding
One way to cut down on or get rid of background noise in electronic systems is to put filters on the cables where the noise is coming in.
To do this, you could add ferrite clamps to a cable to make it more inductive.
For DAQ systems to have less noise problems, they must be designed and installed with proper grounding and ground bonding.
Setting up a ground plane can help cut down on noise and make sure that all circuits in a system have the same reference potential so that different signals can be compared.
Reducing Bandwidth
Reducing the system's bandwidth is another good way to cut down on signal noise.
This is the same as shortening the time it takes to measure a digital signal.
If an amplifier has the same bandwidth as the signal it is amplifying, it will add less outside noise than one with a higher bandwidth.
Techniques for Removing Background Noise from Audio or Video Recordings and Best Practices for Preventing Background Noise
Removing Background Noise
There are different ways to get rid of noise in the background of audio or video recordings.
One way is to use a filter, like the Noise Reduction audio effect in TechSmith Camtasia or the noise reduction effect in Audacity, which involves isolating the clip and clicking Effect > Noise Reduction > Get Noise Profile.
There are also software tools like Krisp, Wavosaur, Samson Sound Deck, Wavepad, and NoiseGate that can be downloaded and used to cut down on background noise.
Preventing Background Noise
There are a few best practices that can be used to stop background noise from being recorded.
One effective approach is to record in a quiet environment.
This can be done by making the space between the subject and the microphone smaller and the space between the microphone and the noise bigger.
When possible, it is also important to get rid of sources of background noise.
For example, you could turn off nearby air conditioners or move to a new place with less traffic noise.
Using directional microphones can also help reduce background noise by focusing on the sound source and minimizing sounds from other directions.
Windscreens and Microphone Boost/Gain
Using good windscreens on microphones when recording outside is another good way to keep background noise from getting in the way.
Depending on the device used to record sounds, changing the level of the microphone's boost or gain can also reduce noise.
Action Plan
Lastly, it is important to learn how to deal with background noises and make a plan for what to do if unexpected noises happen during recordings or meetings.
This can help improve the sound and make background noise less noticeable.
Eliminating Background Noise in Communication Technologies
Noise in the background can be a big problem during online meetings or video calls.
There are a few ways to get rid of background noise from computer microphones or headsets, which is good news.
Using Built-in Noise-Canceling Features
Many forms of communication have built-in noise-canceling features that make it easier to hear during meetings or calls when there is background noise.
For example, Microsoft Teams' desktop app and iOS app both have three levels of noise suppression to help meeting participants stay on task.
Using Third-Party Background Noise Removal Apps
Another way to get rid of background noise is to use apps like Krisp, which use AI-powered technology to cancel out noise in the background.
When used with other communication tools, these apps can improve the sound quality of calls.
Soundproofing the Room or Changing Location
You can also get rid of background noise by soundproofing your room or moving.
During communication sessions, simple changes like closing doors and windows or moving to a quieter room can help cut down on noise interference.
Adjusting Microphone and Speaker Placement
Changing where your microphone and speakers are placed can also help cut down on background noise.
If you put the microphone closer to your mouth, it can pick up your voice over noisy background sounds.
Keeping the speakers away from the microphone can reduce the amount of feedback and background noise.
Using Neat Devices
Neat devices automatically eliminate background noise for phone calls by creating a virtual bubble for your meeting and reducing noise without muffling participants.
The smart microphone and speaker bar technology in Neat helps make audio sound crystal clear and cuts down on background noise.
Minimizing Background Noise in Everyday Environments
Noise in the background is a common problem in homes, schools, workplaces, and public places.
There are a number of things that can be done to reduce or get rid of background noise.
Sources of Background Noise in Everyday Environments
Some common sources of background noise in daily life are:
- Industrial sources such as textile mills, engineering plants, printing presses, and metal industries.
- Loud appliances with tumbling drums or whirring fans in homes.
- Noise in schools, such as in classrooms, cafeterias, hallways, and playgrounds.
- Occupational noise in heavy industrial and manufacturing environments, such as farms, cafeterias, or bars.
Strategies for Minimizing Background Noise
- Use of Earplugs and Barriers.
Use earplugs or noise-cancelling headphones to cut down on or get rid of background noise.
These can be worn at work or while sleeping to reduce the amount of noise from the environment.
Walls, doors, and windows can also be used to cut down on vibrations and loud sound waves.
- Use of Quieter Appliances.
In homes, loud appliances like tumbling drums or whirring fans should be replaced with quieter ones.
This can cut down on noise in the home by a lot.
- Use of White/Pink Noise Machines.
White noise machines can also be used to cover up background noise because they make a steady sound that helps drown out other sounds.
But white noise machines may not be the best choice in all situations because they can also add to the noise level.
- Acoustic Treatment.
Using materials like panels or tiles to absorb sound waves and cut down on reverberation time is called acoustic treatment.
This can be especially helpful in classrooms and other places where learning takes place where noise in the background can be distracting.
- Engineering Modifications.
In places of work where there is too much noise, employers should figure out which areas or tasks cause too much noise and take steps to cut it down.
This could mean making changes to the noise source or the workplace environment using engineering.
Examples include:
- Using sound-absorbing materials in walls, floors, and ceilings.
- Enclosing or isolating noisy equipment.
- Installing barriers or sound curtains to block or absorb noise.
- Personal Protective Equipment.
When technology is not enough to solve the problem, people should also be given personal protection gear like earplugs or earmuffs.
Overall, there are a number of ways to reduce or get rid of background noise.
These might include making changes to the source of the noise, using personal protective equipment, rearranging furniture, using acoustic panels, planting trees, using white/pink noise machines, or replacing loud appliances with quieter ones.
Eliminating Background Noise in Electronic Systems
Active Noise Cancellation (ANC)
Active Noise Control (ANC) technology is used in the business world to cut down on background noise in electronic systems.
ANC technology works by recording the background noise, inverting the noise signal to make "anti-noise,and then adding it to the output signal.
ANC can be done either with analog circuits or by processing digital signals.
Digital Noise Reduction (DNR)
Digital Noise Reduction (DNR) schemes are made to lower the amount of sound that hearing aids make when there is noise.
DNR algorithms look at the waveform of the background noise and make a signal that either changes the phase of that frequency or makes it weaker in real time.
Digital Active Noise Cancellation (ANC) technology cancels out background noise by >40dB, which is the best on the market.
Advanced Algorithms
Advanced noise suppression can be done with the help of advanced algorithms.
Dual omnidirectional microphones or quad omnidirectional microphones are used to pick up sound signals from the environment.
These audio signals are sent to a digital signal processor (DSP) that uses algorithms to help separate and get rid of background noise.
With more advanced algorithms, this could include isolating and amplifying speech so you can hear and be heard clearly no matter how loud it is.
Active noise cancellation, digital noise reduction, and advanced algorithms are all advanced methods used in industry to reduce background noise in electronic systems.
You can do these things with analog circuits or digital signal processing, and you might use two or four omnidirectional microphones to pick up sounds from the environment.
In the end, advanced noise suppression helps separate and block out background noise, which makes speech clearer and lessens unwanted sounds.
How to Remove Background Noise in Audacity
Tip: Turn on the caption button if you need it. Choose “automatic translation” in the settings button, if you are not familiar with the spoken language. You may need to click on the language of the video first before your favorite language becomes available for translation.
Can these noises be useful?
| Used in: | Description: |
|---|---|
| Sound masking: | In some places, like open-plan offices or hospitals, it can be hard to keep your privacy and keep people from bothering you.Sound masking is one solution.This is when background noise is added on purpose to make it harder to hear conversations and other sounds.For example, a white noise machine or a natural sound generator can be used to create a soothing background sound that covers up the more distracting sounds in the environment. |
| Audio watermarking: | Audio watermarking is a way to track where an audio signal came from or who owns it by adding a unique identifier or code to it.One way to do this is to add a certain type of background noise to the audio signal that humans can not hear but that can be picked up by software or equipment with the right kind of sensors. |
| Signal processing: | Some signal processing tasks, such as speech recognition or image processing, can be made more accurate by adding a small amount of background noise.This is because background noise can help reduce the effects of overfitting or bias in the system and make it more resistant to changes in the input. |
| Audio or music production: | Background noise can be used in a creative way to add texture or atmosphere to a song or recording.For instance, the sound of rain or traffic can be used in the background of a song to set a certain mood or scene. |
| Testing and judging: | During testing and evaluation, background noise can sometimes be added on purpose to electronic systems to make them more like the real world or to test how well they work under stress.For example, a car manufacturer might test the electronic system of a car in different kinds of background noise to make sure it works well in all situations. |
Conclusion
In the end, background noise is a big problem in the world of engineering that is often overlooked.
As we have seen, it can affect the quality and dependability of electronic systems and can be hard to get rid of completely.
But the good news is that there are many ways to cut down on its effects, from simple ones like shielding and grounding to more complex ones like signal processing algorithms and active noise cancellation.
Engineers can make electronic systems that are strong, reliable, and efficient by knowing where background noise comes from and what they can do to get rid of it.
So, the next time you come across a noisy electronic system, remember that background noise is not just an annoyance; it is also an engineering challenge that needs creative solutions and technical know-how.
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