The 3 Most Important Audio Effects for Mastering Interview Audio

Tristan Gardner
June 13, 2020
Oftentimes when starting out in video production and editing, many developing filmmakers tend to focus all of their attention on solely the visual components of their projects. While creamy speed ramps, drag-and-drop zoom transitions, and fake lens flares are great, it’s equally important to match those video tracks with high-quality audio. From soundtrack composition to crispy dialogue, the auditory experience is just as important for viewers (if not more, in many cases) as the visuals themselves. In this article, we’ll be taking a quick look at the three most important effects for mastering interview audio. 

There are many different styles of video in the corporate and commercial video genres that require interviews to facilitate the narrative and flow of the story. For example, you may be crafting an overview video for a brand where the CEO is recounting the company’s founding story, or you might be producing a commercial documentary that requires interview footage with a high level of warmth and clarity. Whatever the situation, reducing background noise, equalization, and compression are the critical first steps to mastering interview audio.  

Noise reduction and audio restoration

Unless you only record interviews in a room covered with acoustic foam and your equipment makes no noise, you will need to reduce the background noise in your recording. Lights, monitors, and HVAC units are just a few examples of often unavoidable sounds that can create consistent hums and buzzes outside of a controlled studio. 

When applying noise reduction to an audio clip, make sure you don’t reduce noise at the expense of the interview dialogue quality. The noise reduction effect takes a sample of consistent and unwanted frequencies and cuts them out of the overall clip. High noise reduction levels can potentially cut out too many frequencies which can lead to dialogue having glitchy artifacts or sounding robotic. Also consider that a clip recorded with a lavalier microphone may not need much noise reduction while a clip recorded with a shotgun mic may have more machine rumble or fan noise. 

For a more detailed explanation, check out this guide on Mastering Interview Audio that walks you through every step of the noise reduction process in Adobe Audition. 

Equalization (EQ)

Equalization is the balance of audio across different frequencies. The human ear can recognize sounds between 20 Hz and 20,000 Hz. Different ranges of frequencies are responsible for certain acoustic qualities in a vocal. These ranges will vary slightly depending on the timber of the subject’s voice. For example, most of the fundamental frequencies for a female vocal will typically reflect higher frequencies than for a male vocal. 

Regarding the EQ of interview audio specifically, your attention should be generally focused on shaping the following range of frequencies to achieve different acoustic effects:


Remember to consider mic type and placement when mastering the EQ of a vocal. Different mics have varying propensities to capture certain frequencies of audio better than others. A shotgun mic may have better sounding highs which lead to crisper audio, but it may also be lacking some lows. A lavalier mic on a subject’s chest may pick up warm lows but may need a boost of clarity in the highs. Overall, you want to make subtle adjustments that add missing vocal qualities or remove unwanted frequencies.  

Multiband compression

Generally speaking, compression amplifies low dB levels and reduces high dB levels based on a given threshold across a range of frequencies. Think of compression like you’re squeezing really loud sounds and really low sounds together to make a more consistent vocal volume across all frequencies. Multiband compression is a specific type of compression that allows you to change compression of different bands of frequencies giving you a more fine-tuned compression across all audible frequencies. It’s more advanced than throwing on a single-band compressor and tightening all frequencies and their levels together. 

A typical multiband compressor will have 4 adjustable bands of frequencies that allow you to individually adjust compression for lows, low mids, high mids, and highs. See how the bands in the image below are separated by three white lines. Within each band, you can change settings for threshold, gain, ratio, attack and release. For all bands, there will also be some form of output gain and limiter to amplify and/or squash your compressor’s overall dB level. 

Multiband compressors not only smooth out audio dB levels across frequencies, they also add power and drive (or remove such) to the vocal. Need some more apparent warmth in your clip? Add 1 or 2 dB of gain to the low mid band. This will drive the low mids. Are the “-s” sounds a little too harsh on your ear with the compressor on? Take away 1 or 2 dB of gain in the high band and maybe increase the threshold. For a more in depth look into how to use a multiband compressor and all of its features, check out our guide Mastering Interview Audio

Conclusion

In mastering your interview audio, it is critical that you use noise reduction, equalization, and multiband compression for crispy clean audio at minimum. Remember that there are a number of other effects that can be useful in mastering interview audio such as dereverb, desser, click remover and hard limiter. Paying attention to certain frequency ranges in your equalization and compression will allow you to control the feel and quality of your audio the same way you do your visuals.