# AUImplementorStringFromValueCallback A block called to convert a parameter value to a string representation. ``` typealias AUImplementorStringFromValueCallback = (AUParameter, UnsafePointer?) -> String ``` ## Discussion This block is only of interest to audio unit subclasses. The block returns a string representing a parameter value. The block takes the following parameters: - param: The parameter that contains the value. - value: The parameter value to be converted. ## See Also [`implementorStringFromValueCallback`](/documentation/AudioToolbox/AUParameterNode/implementorStringFromValueCallback) The callback for providing a string representation of a parameter value. --- 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)