Sound Recording: The Basics

by Brenda Soto, emdt alum

Part of the process that we need to incorporate in our projects is audio. Some assignments are podcasts or any type of video that in most of the cases needs music, voice overs, sound effects, among others.

Our projects are very important and for most of us are going to serve for proposals or portfolios. That is one of the reasons for this blogs. I have noticed through all classes that students have common concerns about audio recording. I will be talking about sound recording basics to create a good quality product.

I want to recommend you to acquire a microphone instead of recording the audio with your computer built in microphone. Some options that are not very expensive are dynamic microphones. This microphones are not very expensive and can be accessible for all type of budgets.

Other tool that you will need to record is a software. You can try free downloadable softwares or licenses software. For example, a free software is Audacity. This software include the basics options to record a good quality audio. The important when recording is starting with the sample rate and bit depth, but we are going to be talking about that later in this blog. Other Softwares options, a little more expensive for recording, are Sonar, Cubase , Nuendo, Logic and Pro Tools. The last one is considered the standard recording software from the industry. Also, Pro Tools requires an interface to work.

No matter which program you select, the most important thing when recording is the sample rate and bit depth. For a high quality audio is recommended to record at a sample rate for music or voice of 44,100 Mhz (44.1Khz) and 24 bit depth (depending of the interface allowance). If you are working with video it is recommended to record at 48,000Mhz (48.1Khz). Other thing to consider is the audio format. The standard is the BWF (.wav). This runs in any computer. You can try also the Aiff format but this is mostly used in Macintosh.

When exporting the audio that was recorded, we need also to select the output format (.wav, .aiff, .mp3, etc), sample rate and bit depth. It is very important to make the right choice depending on your deliver channel. If you are going to import the audio to a video editing software to use it as music background, voice over etc, is recommended to conserve the higher quality. Every time that you compress a file, it will reduce quality. For example if you select when exporting for the first time a 32 Khz sample rate you are reducing frequencies. If you bring this media to another editing software and export with lower frequencies, then you are reducing even more the lower quality that you made before.

You can make a test. Why don’t you try to record a phrase or sentence and export it with different type of frequencies? After doing this tests, listen to each of the sentence to notice the difference between each one. Since lower the sample rate, lower the quality because most of the frequencies are cut.

I hope this blog with a brief description of the basics can help you in your projects creation. Also, to continue understanding about exporting media, you can review information about codecs & audio filters. Some example for dynamic effects are Equalizer, Compressor, Limiter, Gate, etc. Also, we have the time based effects like delay, reverb (most of the people call this ECHO, but is completely different), modulations, among others.