VO Recording Software: Some Spectral View Basics – Tuesday Tech Tip

When you start capturing your voiceover auditions or audio, you’ll fin that most of the computer-based recording software renders the audio in a similar fashion In any common recording or editing software you are likely to use, the audio shows up on your screen as a waveform.

Any time we use a microphone, we are capturing the increase and decrease in air pressure. This is how we perceive sound. The greater the pressure, the “higher” the wave onscreen. Higher pressure means louder volume.

Waveforms Easily Show Recorded Volume

Waveforms provide a clear image of the volume.

The “peak” (the highest point) of the waveform is usually what we measure on the dB (decibel) scale. We quickly learn that the taller the wave, the louder the recording. Waveforms also provide an understandable image of sound’s linear nature – everything happens in a timeline, which makes editing easier to learn.

When we start to work more with common editing software, this becomes second nature and we get a sense of the relative volume in our audio as it flows past.

Waveforms Do Not Easily Show Frequency

However, those Waveforms do not provide any quickly usable frequency or pitch information.

Another approach is Spectral view. Perhaps you have seen this as an option in your DAW (and there are both poor and excellent implementations of it inside of various recording/editing software). You may have noticed it or accidentally switched to that viewing mode. It is visually quite different, but can be a very powerful way to view your recordings.

What Does a Spectral View Show?

Spectral view renders the frequency information to your screen. It sets up linearly the same way: i.e. the sound generally moves from left to right.

Rather than wave amplitude (positive and negative values centered around mid-zero point), Spectral views plot FREQUENCY in the vertical axis from low to high. The low frequency components of the sounds are at the bottom and the high frequency components of the sound are at the top.

Where you see brighter colors (usually from dark orange to bright-whitish, or from deep reddish to bright yellow-white) is where the more intense frequencies live. Dark areas mean that there is no sound at that frequency.

If the spectral data is handled well (as in Izotope’s RX interface shown above), you should be able to see things like low frequency rumble (kind of a diffused “fog” at the bottom of the screen) and the “base” frequency of your voice recording. Human voice generally varies slightly in pitch (which is another name for frequency), so it will fluctuate somewhat over time. (If you record a fixed-frequency instrument like a piano, the notes will track in a level bar as the pitch won’t change).

Looking above the base vocal frequency, you may see visual “echoes” which are the harmonic components that combine to give your voice a distinctive tone. Those are the overtones of your voice.

Beyond that, you may notice vertical plumes of bright where you had a sibilant “S” sound (sibilance is broadband noise – so it has energy at most frequencies). Or if you see a general light “fog” when you aren’t speaking, that might indicate audible background noise. (It depends upon how “bright” the fog is…)

Spectral is a tool worth learning

Viewing in Spectral takes practice. I forced myself to use it for several months before it became second nature and I could anticipate how things would sound from the visuals.

Just as with waveforms, we still don’t want to draw huge conclusions without listening first. Going only by the visuals can cause us to chase flaws which are inaudible and simply don’t matter.

But using a Spectral view can provide a quick visual reference to diagnose problems.

Spectral tools vary with different software

Some software (such as Izotope’s RX or Adobe Audition), allows you to directly edit sound while in Spectral mode. This enables a graphical approach similar to photo editing software, amazing for negating odd noises which ruin a perfect take. (Though it might be simpler to just get back in the booth and do it again). Not all spectral-view-ready DAWS offer direct spectral editing.

There is one weird thing about this way of viewing the audio – with a Waveform, as you zoom in you gain detail. It’s why we can easily use Twisted Wave to find the tiny click that we know is there. But, in Spectral you actually lose detail as you increase resolution.

There’s actually a good reason for this, but I did promise there would be no math today… The takeaway is that past a certain point, Spectral view renders the data less precisely. That just means that if you lose your way, simply back off the magnification.

RX Elements (often on price promotion through Izotope) now includes a Spectral view, which means that this has become accessible to more VO’s. It can help you to see the detailed parts of your audio recordings, and it’s worth a look!

Adobe Audition is another recording software option which includes a Spectral view option.

Now, go be brilliant!

Each week, I send a “Tuesday Tech Tip” to my email community. It includes technical tricks I’ve come across, refinements for voiceover workflow, and insights gained as a working voice actor and VO technical audio consultant. If you would like to receive these as soon as they come out, please take a moment to sign up here. Thank you.