How to remove noise from a recording. How to extract audio from a video into a separate audio file
Hi all! Sound normalization is not a problem for those who know how to use Audacity even at the most basic level.
Let's start with a definition.
To normalize sound is, simply put, to process it in an audio editor so that it is pleasant to listen to, namely:
- remove background noise,
- equalize the volume of speech throughout audio track,
- remove sharp emissions/peaks in volume,
- remove unwanted sounds (cough, for example),
- make the recording volume such that it can be comfortably listened to on all types of computers and mobile devices, setting the device volume to medium level.
How important is it? Very important! Nice video from bad sound- money down the drain. Video “rules” in Internet marketing. Whether you are selling through your online store, promoting your services online, building a corporate website, or trying to boost your Youtube channel - you need to be able to make a decent video everywhere. But video is video, and if your soundtrack is quiet, muffled, with noise and other defects, then consider all the work in vain. No one will continue to watch such a video for more than 10 seconds.
I’ll say right away that if you rely on your ultra-modern expensive professional video camera, then it’s in vain. It will record noise even better than a smartphone. So it’s not possible to “extract” the sound 100% with first-class hardware.
Professionals use it for this sound editors. They take a separate audio track and edit it. In this post, I will teach you how to use Audacity to normalize audio.
Why Audacity? Because it:
- A specialized program is an audio editor for sound files.
- Powerful enough to do anything with sound.
- Free.
- Quite easy to learn. Especially when it comes to standard, simple operations with sound.
Well, let's get started.
From this article you will learn:
In order for everything to be as close as possible to real life and it’s clear, let’s take a video recording made at the very regular smartphone – htc one v. He shoots video in HD resolution. Today this is no longer something prohibitive, but a standard. The sound captures like a smartphone - if close, then it’s good, if at a distance, then it’s mediocre.
So, our very first task:
How to extract audio from a video into a separate audio file
There are a lot of ways. In order not to clutter the post with minor details, I’ll briefly tell you about just three. Choose one that is convenient for you.
- Through demon paid program Freemake Video Converter
- Through the paid program Total Video Converter
- Using your existing video editor. And you must have it. Especially if all or part of your business is online. Especially if you regularly shoot and post videos on your website. Of course, if you want to post good video so that a lot of people can watch it.
The first two points are not worth explaining in detail. Everything there is completely simple, but if you have any problems, write to me and I’ll explain.
I’ll dwell on the video editor in more detail. I mean how to extract sound from a video using it. There are also a lot of video editors. I use one of the most popular - Sony Vegas.
We copy the captured video from the smartphone to the computer.
Open the video editor.
Using the File – Open menu, open the video file.
and select the format of the saved file mp3. Click on Custom...
and select saving options. I recommend choosing Mono, bitrate 128 kbps and frequency 44,100 Hz.
Select the save folder and the desired name of the saved mp3 file.
We saved the entire audio track separately and now let's start normalize sound. I'll describe everything step by step.
Step 1. Initial use of the Hard Limiter plugin
The recorded sound may contain loudness peaks. If they are not reduced, they can become very annoying or even deafening. It could be a cough, a suddenly loudly moved chair, a horn from a passing car, and so on. That's why:
Click on the track properties control area with the left mouse button and thereby select the entire track
Then go to the Effects-Hard Limiter menu... and set these parameters
Click OK. Ready.
Step 2. Normalize the sound
Usually, recordings from microphones, smartphones, and voice recorders turn out to be quiet so that they can be posted directly in this form as a video on YouTube. So we need to raise the volume of the sound. But it is advisable to do this so that the sound rises, but not above a given limit. The Signal Normalization plugin is used for this. It increases the volume, but in such a way that the maximum amplitude is fixed. To do this, go to the Effects menu - Signal Normalization... Set the box to -3.0 db.
Click OK. Let's look at the result.
Step 3. Processing the audio file with the Compressor plugin...
Let's continue use Audacity For sound normalization and at this step we will master the Compressor plugin... Please note that you need to process the track in exactly this order step by step, without confusing or skipping. What is a Compressor for...? The compressor averages out, reducing the difference between the quietest and loudest sections. It happens that a person speaks into the microphone either louder or quieter, and if the difference is too big, listening to such a recording is uncomfortable. After processing with a compressor, the voice volume becomes more even, without jumps.
So let's go to Effects-Compressor... Set the same parameters
and click OK. We are happy with the result.
Step 4. Finishing with the Hard Limiter plugin...
No matter how well the Compressor processes sound, its algorithm also has shortcomings and under certain conditions it again highlights peaks. To avoid this, process the track again with the Hard Limiter... plugin, just set the level not to -10, as the first time, but to -2.0 db.
That's all. In most cases, these 4 steps are enough. Now let's look at more complex cases, namely:
- if the previous plugins - Signal Normalization... and Compressor... - did not do a very good job of normalizing the volume along the entire length of the audio track
- and if the recording took place at high level background noise - a refrigerator was working nearby, a fan was making noise, some kind of humming, etc.
Manually leveling the volume of individual sections of an audio track
To do this, use a simple Signal Boost plugin. It acts as a volume knob. At this stage, its use is justified, since the sound has already been driven through Signal Normalization... and Compressor... and in general represents a diagram leveled without jumps. Only, as you can see, it is globally different in large areas. Previous plugins do not always cope well with this “situation”, so now we’ll fix it manually. I note that this situation does not happen often.
So, we highlight that part of the audio track where the signal level is clearly lower. We go to the menu Effects-Signal Gain... and by selecting the gain level we achieve equalization of the audio track fragments in volume. Watch the video to see how this happens.
How to remove noise from a recording
Please note that now I will explain how to deal specifically with continuous background noise. If suddenly during the actual recording someone coughed, sneezed, or something fell, this is not background noise and if you want to remove it, then you need to do it in other ways. Now we will remove the background noise. So, to remove noise from audio, you need to find a section of silence on the audio track, highlight it and listen carefully. It is desirable that it contains only smooth background noise, without clicks or other “dropping out” or prominent pieces. The better we select such a fragment, the better quality program will cope with stripping the entire audio track.
To do this, visually select an area on the diagram with zero or so amplitude and select it with the mouse. Click on Play button in the Audacity button bar and listen carefully. If there are other isolated sounds in the background noise, then we try to find and highlight a fragment without them.
Having found the best fragment, we select it. Go to the menu Effects-Noise Removal-Create Noise Model.
Then select the entire track. Go to the menu Effects-Noise Removal. Leave these parameters here
The only setting you can experiment with is Noise Reduction. The very first field. I advise you to stay within 12-24 db. If you set it below 12, the noise may decrease quite slightly. If you make it higher than 24, distortion may appear in the remaining areas with sound.
Let's watch the video where I do all this:
That's all. The audio track has been normalized, all that remains is to save it as a file.
Saving an Audacity-processed track as a separate audio file
This is done through the File-Export menu... Please note that through the File-Save Project menu... you will save the audio recording in Audacity format and only. In order to save in mp3 or wav format you need to use Export... Then everything is simple. Select the desired file type. If necessary, click Settings... and set required parameters. For example, if you export to mp3, then you can select the audio quality through Options. I recommend not making it lower than 80 kbit/s and higher than 128 kbit/s. This is for the voice, of course. If you wrote music and you need maximum sound quality, you can even set it to 320 kbps. Just keep in mind that the higher the bitrate (this is the sound quality), the bigger size the final file will be obtained.
So, from this post you learned how use Audacity in terms of sound normalization.
Updated December 2018 — This article was written in 2014. Over the past 5 years, by the end of 2018, experience has accumulated, subtleties and techniques have emerged that:
- simplify the procedure,
- reduces sound processing time and
- significantly improves the quality of the final sound
Do you want a sharp decline in rankings and traffic? If not, then this post will be extremely useful to you. Because this can easily happen if you suddenly remove text from the promoted page.
From our experience, this has happened more than once. To start, better imagine the situation:
The site is progressing successfully. All of its positions are constantly growing and rising to the top places in the results search results. As a result, traffic to this site is growing normally.
But at one point, you decide to modify the site a little, or simply change its design. You do this and accidentally remove text from the main page.
We removed the optimized text, which slightly repeated the main keywords.
Let's say this home page, and she was promoted using 15-20 keywords.
Do you know what usually happens?
Main consequences:
- positions are falling
— attendance is falling
It looks like this - positions:
And so, according to the decline in attendance:
IN in this example, promotion of an English-language site from which the text for the promoted page was removed. The main search engine is Google.
Let's take a closer look
If you don’t want the same thing to happen to your site, then at a minimum you need:
- Do not abruptly remove text from the page
- If you change the text, then to a new one
- You can quickly remove without consequences on a site that is under sanctions from search engines
Everything is extremely simple, but sometimes developers forget about it, and projects lose traffic that brings in money.
Observations
If you replace the text with another one, you can also get completely different results. For example:
A) Temporary subsidence
This applies not only to Google, but also search engine Yandex. Temporary subsidence of positions can be from a couple of days to more than a couple of weeks.
It all depends on the text with which you replaced the previous one. If it is better, but in the end the site itself will also be better in terms of traffic. But usually not right away.
B) Rapid improvement
After changing the text, the page may also give better result. For example:
— previously the text was optimized for one core keywords
— and then replaced new text to the old one
As a result, in most cases, positions and traffic on the site only improve.
B) Strong subsidence
It happens that the new text on landing page, only makes the site worse.
For example:
- replaced old text on new
— it was made more dense and optimized
As a result, the site page drops significantly in positions and does not return to good positions.
Finally
In fact, the situations may be different. The most important thing is how you react to them.
In internal optimization the text still plays a role, so it is worth presenting it not only for SEO, but also for the benefit of the visitor.
Good articles to follow:
PS: What situations did you have? Let's discuss!
Most housewives actively use vinegar for cleaning and preparing various dishes. This substance is also indispensable in the process of home canning. The acetic acid contained in vinegar perfectly removes stains, eliminates unpleasant odors, and kills mold and bacteria. Only the vinegar itself doesn’t have a very pleasant smell. How to remove it?
Read in this article:
Neutralization of the outbreak
To get rid of vinegar odor, you first need to identify and eliminate the source of the obsessive vinegar odor. Often, vinegar spilled on a surface or object saturates it and nearby things. How to do it?
- If your body smells like vinegar. The stained area should be rubbed with salt and then washed with soapy water. Once it dries, there will be no scent.
- A vinegar aroma may remain on your hair after using treatment masks. In this case, you need to dilute a tablespoon of baking soda in a liter of warm water. Wash your hair with baby soap, and then rinse with a soda solution. If necessary, the procedure can be repeated.
- If the carpet smells, alcohol and powder will help. Two tablespoons of powder and one tablespoon of alcohol should be diluted in eight to ten liters of water. Stir the solution thoroughly, rinse a rag in it and wipe the stained area with it. Then walk over the surface with a dry cloth.
- Shoes and clothes smelled. The outfits can simply be washed and carefully dried in the wind. When vinegar has spilled on your shoes, you can wipe the stained area with a cotton swab soaked in ammonia. Afterwards, the alcohol is washed off with water, and the shoes are dried well.
- Surfaces. Even the most persistent vinegar scent should disappear after about 12 hours. If you have no desire or strength to wait, it will help baking soda. It is enough to pour it on the place of smell and leave for a couple of hours. After time, wash off the powder and wipe the surface with a dry cloth. The procedure can be repeated.
- What if there is a smell from the refrigerator? IN in this case Baking soda will also come to the rescue. It should be poured onto a saucer and left in the refrigerator for a day. The trouble will disappear without a trace. If your dishes suddenly smell like vinegar and you need to clean it up, you can wash the plates and pots in hot water and salt.
Ventilate the room
When the fight against persistent unpleasant odor is over, the room needs to be thoroughly ventilated. To do this, you need to open all the doors and windows for an hour or two. Sometimes, when the aroma is very strong, it takes longer to ventilate, up to several days. One way or another, he will be able to get out. An ozonizer will help speed up ventilation. This device not only purifies the air in the room, but also reduces the content of harmful substances. An ozonizer is especially useful when someone in the household is sick.
Fragrances - into battle
It is clear that if something smells like vinegar, flavorings cannot eliminate it. They simply mask the smell. And in some cases they make the air heavier. Therefore, such “disguise” can only be used in an apartment with the cleanest air. Tea, herbal mixtures or coffee beans can be placed in fabric bags and hung in different places Houses. They will give off a light, pleasant aroma.
Modern cleaning products and plenty of fresh air most often help prevent troubles like “your favorite sweater smelling like vinegar.” If this nevertheless happens, in order to remove the smell of vinegar, it is enough to eliminate the source of “odor” and replace it with pleasant aromas.
Many people are familiar with the situation when, due to a strong unpleasant odor, others know that yesterday we took a significant dose of alcohol. If friends understand everything correctly, then colleagues will be wary, and problems may arise with the boss. To avoid troubles at work, you need to get rid of the smell of fumes and quickly get yourself in order. We'll look at everything best methods, allowing you to do this, but let's start with theory.
Fume- these are unpleasant-smelling breakdown products of alcohol that appear 60-90 minutes after taking the first dose of a strong drink (beer, vodka, etc.), when the liver begins to process alcohol into harmless acetic acid.
Many people confuse fumes with the smell of alcohol, but in fact these are two different “aromas” that can emanate from a person at the same time, enhancing each other. The methods of dealing with them are also slightly different.
Contrary to popular belief, the unpleasant smell of fumes does not come from the mouth or stomach. Acetic acid, which causes fumes, is excreted through the lungs and, to a lesser extent, through urine and skin.
The smell of fumes lingers until all toxic remnants of ethanol breakdown are removed from the body. Depending on the dose taken, complete cleansing takes from 3 to 36 hours. Therefore, it is impossible to quickly remove the fumes; you can only suppress it for a short time using various means.
The fume itself is harmless, it only causes discomfort for others. But if there is a baby in the house, then he should not be in the same room with a drunk parent. Nervous system for young children is unstable; due to the unusual pungent odor, the child may cry and have difficulty sleeping.
It happens…. Simple ways to remove fumes
This problem has one reason - the toxic breakdown products of ethyl alcohol. Their removal improves well-being and removes unpleasant odors. But first, let’s look at ways to quickly “disguise” in case of emergency.
1. Chewing gum. Simple available method, which allows you to quickly eliminate the smell of fumes. Disadvantage: it lasts for a maximum of 10-15 minutes. It is believed that mint chewing gums are best, but in fact they are too harsh and mixed with fumes give an unpredictable result. I advise you to buy fruit-flavored chewing gum.
2. Oral hygiene. To avoid the smell of fumes, you can brush your teeth or use a special refreshing spray. These products, like chewing gum, act for up to 15 minutes, only interrupting the smell. But for the sake of overall health of the body, I recommend starting the fight against fumes with thorough brushing of your teeth.
3. Other flavors. The most accessible thing at home is to chew parsley, nutmeg, coffee beans or regular roasted seeds for 2-3 minutes. This will be enough to reduce the fumes for about 30-40 minutes. Disadvantages – listed folk remedies they themselves have a pungent odor.
Now let's move on to effective ways remove fumes. True, they are not very fast; the result becomes noticeable after 6-8 hours.
4. Drink plenty of fluids. Coffee, black and green tea stimulate the kidneys and have a diuretic effect, helping to remove residual alcohol. But you can drink them only if there are no heart problems and blood pressure. One cup every 4-5 hours will be enough.
Mineral water, herbal decoctions (oats, dandelion, chamomile) and freshly squeezed fruit juices restore the mineral-acid balance of the body, fighting the cause of fumes, and not its consequence - an unpleasant odor.
5. Proper food. To improve your overall well-being, I advise you to eat a bowl of soup or borscht, as well as scrambled eggs. The first two dishes are rich in vitamins, scrambled eggs are rich in protein and amino acids, which help the liver process the remaining ethyl alcohol. For dessert there is fruit. Watermelon, strawberries and wild strawberries have a diuretic effect.
6. Physical activity. First of all, you need to take a walk in a park or square. fresh air 20-30 minutes, or at least open the window in the room. Light charging won't hurt either.
To activate your lungs, I advise you to perform breathing exercises. There is nothing complicated about this, just take deep breaths and exhales for 5 minutes. Hyperventilation of the lungs helps to cleanse them, as a result, the smell of fumes becomes less strong. Many people do not believe in this method, considering it useless, but I highly recommend trying it.
7. Water procedures. A warm bath and contrast shower perfectly cleanse skin pores, helping to remove alcohol toxins from the body. The ideal option is to go to the bathhouse, but immediately the next day after the party this is not available to everyone, so you can limit yourself to a bath or shower.
Medicines for fumes
First of all, this refers to the famous “Anti-policeman” and similar means, in the effectiveness of which many drivers believed. But these drugs, like chewing gum, only kill the smell for a while, and then it appears again. It is strictly not recommended to drive after taking such a drug.
Lasts up to 60 minutes Anti-hangover drugs cope well with fumes: Zorex, Limontar, R-IKS 1. But activated carbon and other sorbents are useless, since the cause of the unpleasant odor has nothing to do with the stomach, where these drugs “work”.
To get rid of fumes as quickly as possible, I advise you to simultaneously use several methods related to nutrition, fluid intake and physical activity. In extreme cases, anti-hangover pills will also help. The fumes from beer and vodka go away no earlier than 3-8 hours after the last shot or glass.