Sound effects that hold attention

Your editing software gives you a sound effects library a click away. Thousands of them, a search box rather than a shelf, most of them free, sitting right beside the timeline. Whooshes, impacts, risers, a swipe for every cut you could possibly make.

The existence of that folder is not an argument for using it, and the number of videos that sound like the folder is why this needs saying at all.

A sound effect needs a job: directing attention, clarifying an action, supporting a transition or contributing to the mood. Availability alone is a poor reason to add one.

What is a sound effect doing?

Working on the part of your viewer that is not watching.

Sound can help signal a change of topic or image, including when the viewer is briefly looking elsewhere. Use it where that signal helps the piece.

That is a real job. It is also a small one, which is why a video with a hundred effects in it has usually mistaken the job for a style.

Which uses survive scrutiny?

Three, and it is a short list on purpose.

Covering an edit

A cut can make the room sound jump. First try matching the ambience or a short audio crossfade; an effect may help when it belongs to the scene.

Substituting a sound that did not record properly

The knife on the board, the click of a switch, the lid coming off a jar. A camera microphone across the room either missed it or turned it into a smear. Putting a clean version back is not deception, because the sound happened; your recording chain failed to represent it, and the substitute restores what somebody standing in the room would have heard.

The line is intent. Replacing a sound that happened is restoration. Adding a sound that never happened, so something looks more impressive than it was, is a different activity, and audiences are better at detecting it than anybody would like.

Marking a transition the eye needs help with

A sound can mark the move from a face to a diagram or from one lesson section to the next. Keep the signal distinct enough to be useful.

Why does everything have a whoosh on it?

Because it is there, and it is free, which is the same reason so many videos zoom in for no reason.

A sound arriving on every single cut stops being information almost immediately. The ear learns any repeating pattern quickly, and once it has learned yours it stops reporting it upstairs. The effect is then doing nothing at all except occupying the space where a genuine emphasis could have gone, and taking a small bite out of your voice each time it passes.

The problem is not that whooshes are tasteless. It is that they are self cancelling. Emphasis works by contrast, so the more of it you apply, the less of it you have, and a video that emphasises everything has emphasised nothing while sounding busier than it is.

How loud should an effect be?

There is no figure, and anybody offering you one is guessing about a room they have not heard.

Judge the effect against its purpose. If it masks a word or pulls attention from the thing it should support, lower it, move it or remove it. A deliberately prominent effect can still be right for a reveal or joke.

Effects also compete with speech over the same ground. A riser underneath a sentence is not a background; it is a second thing talking. Either it goes under a gap in the words, or it goes quieter than feels right to the person who chose it, which is you, which is the difficulty.

Take them all out

This is the pass worth doing, and it takes one afternoon on one video.

Mute every effect and watch the edit through. Then put back only the ones you actively missed: the joins that suddenly feel abrupt, the transitions that now land as confusion. Most people restore a small fraction of what they removed and find the video improved in a way they were not expecting, because the survivors finally have room to mean something.

Repeat the exercise when an edit starts to feel overworked. The useful habit is listening for what an effect contributes before reaching for the library.

For the next edit: when your hand goes to the library, ask whether the moment needs a sound, or whether the moment simply arrived while the library happened to be open.

Sources and evidence

What here is established perception and what is our own method.

What is established. That attention lapses and returns, and does so around the moments something changes, is consistent with research on educational video and engagement (Brame). That a repeated sound stops being noticed, the ear ceasing to report a pattern once it has learned it, is habituation, one of the most robust findings in the study of behaviour (reviewed by Rankin and colleagues). And an effect laid under speech competes with it over the same frequencies, the masking that governs any two sounds in one range (Moore).

Our method. Muting every effect and restoring only the few actually missed, and admitting an effect only where it covers an edit or replaces a sound that genuinely happened, is the practice here.

References.

• Cynthia Brame. Effective Educational Videos. pmc.ncbi.nlm.nih.gov. Cognitive load, engagement and active learning should guide educational video design. Review/guideline, not a fixed-length law.
• Rankin C. H. and colleagues. Habituation revisited: an updated and revised description of the behavioral characteristics of habituation. pubmed.ncbi.nlm.nih.gov . Habituation: a repeated stimulus stops being noticed once the response has waned. Review across species and paradigms; describes a robust general property, applied here by analogy to a repeated sound effect.
• Brian C. J. Moore. An Introduction to the Psychology of Hearing (6th edition). books.google.com. Auditory masking / frequency selectivity / critical band: two sounds sharing a frequency region, the louder hides the quieter. Used in mixing-a-lesson-so-people-can-follow-it and sound-effects-that-hold-attention. Canonical psychoacoustics textbook; exact masking behaviour is more complex than a simple sum, as the copy states.