DE Oracle @ UMUC

Best Practices for High-Quality Audio

Towanda Jones

Instructional Support Specialist

Center for Support of Instruction

Published: May-June 2009

Category: » Tech-skills-software » Audio

Are you tired of producing poor-quality audio recordings? Confused about what type of microphone to use? Frustrated because you just can't get rid of the ambient noise in your recording? No worries, help is on the way! This article discusses how to get consistent high-quality audio whether you’re using Audacity, Camtasia, or another audio recording tool. Hardware, software, and the environment are the three key factors to keep in mind for producing high-quality audio. If you follow the simple techniques provided here, the quality of your audio will improve dramatically.

Environment

The most important aspect of audio recording is the environment. First, keep the microphone away from laptops, computers, external hard drives, printers, etc. These devices produce an extraordinary amount of ambient noise that can easily be picked up during the recording and ultimately ruin the quality of the audio. Other ambient noises to consider are fluorescent lights, air conditioning/heating systems, and cell phones—they all have a tendency to create unwanted background noise. Depending on where you record, it may be hard to control the environmental noises around you; it’s important to eliminate as much background noise as possible to produce high-quality audio.

Hardware

Invest in a good microphone headset with a USB connection. Avoid microphones that go through the sound card of your computer. Sound cards are typically cheap, poorly grounded, and known for converting audio to digital formats very poorly. They tend to pick up a lot of vibration, humming, and extra noise. With a USB microphone, however, the audio is converted into a digital format before it even gets sent to the computer.

Whatever microphone is chosen, a good practice is to use a pop filter, which is a foam covering that typically comes with the microphone. The pop filter reduces the popping noise when speaking into the microphone. For example, some consonant sounds like f, s, h, and th are difficult to record and cause a lot of breath wind when they hit the microphone. The pop filter filters out those breath sounds and helps prevent them from going into the microphone when recording.

It’s a good practice to speak across the microphone rather than directly into it and to position the microphone away from the mouth. The advantage of speaking across the microphone is that the hissing sounds and loud breathing noises from the speaker will reflect off to the side, so there aren’t any extra noises going into the recording.

Software

Software also plays a role in developing high-quality audio recordings—though how you use the software matters more than which software you actually use.

A best practice is to record in the highest quality possible because you can always compress the recording to an MP3 file later. Don’t worry about the initial large file size; the finished product will be well worth it.

Before beginning the recording, be sure to set the sample rate and the bit depth in your recording software. These two features play a critical role in the quality of your final product.

• Set the Default Sample Rate to at least 48000 Hz or higher, which is the standard for CD quality. (The higher the sample rate, the better the quality of the audio.)
• Set the Default Sample Format to at least 16-bit or higher.

Removing Ambient Noise

Although it is difficult to eliminate all noise from a recording, it is possible to clean up some of the noise with the audio enhancement features in the software. A great tool to use is equalization, which is effective at pushing up the bass, reducing the frequency range, and removing hissing noises in the recording. Software such as Audacity has predefined equalization filters that can be used. The noise removal feature is available in many software products, but it does not work as effectively as equalization and runs the risk of removing actual audio or distorting it because it cannot distinguish between background noise and voices.

Get in the habit of leaving about five seconds of dead air time (time when no one is speaking—total silence) when you begin recording. Dead air time makes it much easier to identify the room noise and eliminate it from the recording during the editing process, and it prevents you from losing information at the start of the recording.

The next time you record audio, follow the tips listed here for the best ways to handle hardware, software, and the environment—and then listen to the difference they have made in the way your recording sounds. You're sure to be pleased!

References

Nesbitt, Scott. (2006, December 10). Tech Tip 105 - Cleaning Up Audio Files with Audacity. Retrieved from http://www.geeks.com/techtips/2006/techtips-10dec06.htm

Pierce, Matt. Best Practices for Quality Audio. Retrieved from http://www.screencast.com/users/VisualLounge/folders/24%20Camtasia%20Videos%20in%2024%20Hours/media/160356e2-d20e-495e-9d0b-1ee634c84bee

wikiHow. Get Higher Audio Quality when Using Audacity. Retrieved from http://www.wikihow.com/Get-Higher-Audio-Quality-when-Using-Audacity