# changeObstruction(by:duration:) Creates an action that changes an audio node’s obstruction by a relative value. ``` class func changeObstruction(by v: Float, duration: TimeInterval) -> SKAction ``` ## Parameters `v` The amount to change the obstruction by, in decibels. `duration` The duration of the animation, in seconds. ## Return Value A new action object. ## Discussion When the action executes, the audio node’s obstruction animates from its current value to its new value. For more information, see . This action is reversible; the reverse is created as if the following code is executed: ```swift let action = SKAction.changeObstruction(by: -v, duration: sec) ``` --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)