Lester White
by on August 8, 2020
Bad audio quality is one of the most frustrating things your learners can subject to. Not everyone has access to quality studio equipment, but that doesn't mean you can't get great audio in your workouts.

In this post we'll teach you how to generate high quality audio for your eLearning courses using a free audio software.

Prevention is better than cure

It is better to set yourself up to record the best quality audio possible than to get a mediocre recording and try to fix it later. In 'post-production' you can do a lot of enhancements to the file, but there are some things that are there for ever once recorded.

Here are a simple steps which will help:

  • Using a decent microphone. In LearnUpon we 're using microphones with blue yeti. They are relatively cheap while being of high quality as well (here's a guide on how to get the most out of them). And using dynamic microphones when you are recording in a noisy environment.
  • Carefully choose your recording venue, protected from street noise etc.
  • Switch off something in the room that e.g. a device or air conditioning produces ambient noise. We recommend sitting in the room and making a short recording, it will help you recognise any ambient sounds when you play it back.
  • If you find your test recording has a low background hiss try to reduce the gain on the microphone a bit. It is typically a microphone button itself.
  • Approach the microphone but don't get too close! Extend your hand fully and the distance to your pinky finger between your thumb is about the optimum distance you should be positioned from the microphone.
  • To make sure you are pleased with the setup run a few test recordings.

Audio editing tools

You have access to a number of different audio editing resources. Even one of the most common ones is free to use. Audacity is an perfect introduction to the world of audio editing. It is open source software created by volunteers.

You can trim files to reduce their length, eliminate background noise, edit silence, change volume and much more with Audacity.To get started download Audacity here.

There are of course other paid solutions that are more feature-rich and easy to use.

For example, Adobe Audition is an integral part of the creative product cloud suite. It is extremely potent. But when you become an audio pro, we propose to save that one for.

Let's run through three really important actions you can do with Audacity, to make an immediate improvement on your audio today-how to remove background noise, how to remove silence, and how to adjust a recording 's audio volume levels.

How to remove background noise

The last thing you want to hear or feel when you are listening back to an audio recording is the background noise. For the listener it is really disturbing. Recording in an environment that completely removes all background noise is almost impossible, unless you are lucky enough to have access to a professional recording studio.

So what can you do to get the most out of what's available to you to create the best audio possible?

Using Audacity, removing some of the ambient noise from your audio track is easy. To do this you need to create a profile of noise. This 'teaches' the software about the difference in your recording between unwanted and wanted noises. The program will then delete any unwanted buzzes from the context.

In Audacity, you can do this by:

Highlighting a recording area, where there were no intentional sounds. Let the mics pick up and record the 'space tone' for a few seconds at the beginning of any recording before someone talks-this makes this process much simpler later.

  1. Then, in the menu options select Effect > Noise Removal.
  2. Click Getting the Noise Profile.
  3. Highlight now the entire recording from beginning to end.
  4. In the menu options select Effect > Noise Removal again.
  5. Select OK button.
  6. The track should be 'cleaned' from unwanted audio, and ready for use.

Removing silence from your recordings

Gaps in silence are a common problem with voice recordings. If your recordings are short you can highlight and erase these areas on your audio file. For longer recordings, this can become a very laborious process. And you'll need to automate the procedure if you want to remove the silence from an hour-long video.

Truncating silence simply doesn't erase the silence. It detects the sound components which are called silence (audio below a certain threshold or level of noise) and then compresses it by a factor. The result is the same as deletion as removing those silent, pesky gaps in your audio.

Here's the way you do it, upload your audio file to Audacity and follow the instructions:

  1. Point out the whole recording with your mouse.
  2. Click on the menu Effect and then Truncate Silence
  3. Audacity requires use of such criteria to assess what silence is. Min Length, Total Length, and Threshold of Silence. Such settings will decide and disable what's called silence.
  4. Compression of Silence determines how much of the silence is eliminated. Audacity compresses it, instead of removing all the silence. For example, a 3-second duration of silence will be compressed down to 1 second using compression 3:1.
  5. Choose OK button.

Amplifying and normalizing

Is your track too loud for audio? Or not quite loud enough? You can also note, when recording interviews, that the audio may be a little on the low side.

With that handy technique, you can raise the volume. You may also lift some pieces, and then lower some other pieces. Use the amplify option, if you just want to do one.

When you want to increase the volume of one part of the track and then lower the other-Normalize is the way to go with that.

Amplify adjusts the volume of the audio track that you select while maintaining the relative speed. Which means you increase or decrease the volume of all the selected items.

Of instance, if you're editing a recording of a conversation where one voice was too far from the microphone, be mindful that all other voices that were positioned closer to the microphone would increase the same amount of volume.

The Normalize effect gets the recording to a target point at an average or peak amplitude.So, use our example of a conversation again. The silent voice will be raised toward the goal point, while the louder voices will not be raised above that point-to balance the two.

To use either, highlight the track section, or the entire track, where you want to change and then select the Effects button. Choose either Extend or Standardize.

Find out more about Audacity

Inside Audacity there are plenty of other useful and easy to use resources that can take your audio recordings from decent to great. Here you can access the new manual and search their detailed wiki complete with tutorials.
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