What is Asynchronous Sound in Film?
The synchronization of sound so that it aligns with a particular screen image is a common step in filmmaking. But certain sounds are not necessarily synchronized with what’s taking place on the screen. For example asynchronous sound is not synchronized with the screen image. And includes a variety of sounds that can be used for aesthetic purposes. But what is asynchronous sound in film? And what’s the difference between synchronous sounds and asynchronous sounds in film?

Asynchronous Sounds in Film
Asynchronous sounds are sounds that have not been synchronized to the film actions, movements, or visual environments appearing on the film screen. These sounds are often used for aesthetic purposes to express a previous action or to elicit a sound advance.
For example, an asynchronous sound may come through on a film. As the advanced sound occurs when the editor chooses to show a child that is crying in a crib. But over or instead of the crying. The sound of a loud dog barking from the next scene comes into play.
In this example, a mix of synchronous sound (the baby crying) and asynchronous sound (the dog barking but not yet visible on the screen) is used.
Synchronous Sounds in Film
Synchronous sounds include the sounds that have been synchronized to align with the image that is being viewed on the film screen. Unlike asynchronous sounds, synchronous sounds in film have been closely matched to a visible source of the on screen sound taking place.
For example, synchronous sounds are typically those that directly relate to what you’re seeing on the screen. As in the example given above, when the baby is crying in a crib.
Any sound of the baby crying is considered synchronous. Whereas the sound of the dog barking that was also happening, was asynchronous.
Asynchronous Sound vs Synchronous Sound in Film

When comparing asynchronous sound vs synchronous sound in film, a closer look at sound effects is necessary.
Synchronous sounds are typically going to occur in direct connection to what is taking place on the screen. And they make perfect sense because they align with the visual component.
Likewise, asynchronous sounds in film are not going to match with any of the visible sources on the film screen. And could be used to add to the overall realism of the film, provide an additional emotional nuance, or to otherwise add to the film’s setting.
A Harmony for the Audience
Generally speaking, the price that a production company will be willing to pay you for your book to film adaptation rights is about 2-3 percent of the production budget.
So, say the production company has a budget of $10M to produce your book adaptation. That’s considering you have an incredibly popular book like a NY Times Bestseller. Then you’ll be offered 2-3% or $200,000 on the first day of principle photography.
However, most of the time the agreement will also consider a cap. Perhaps the budget is $10M but the cap for rights to the book is set to $225,000.
That means, even if the film budget increases, to say $100M? You’re still only going to get $225,000 for the rights, which is still a rather substantial amount of money.