The Android SDK has an API that lets you access Google Voice Search directly, not having to go through its well known user interface implementation.
A centerpiece in that API is the RecognitionListener interface.
Is there an equivalent to this in iOS 4.2 (and up)?
If so, what term should I be searching for in the iOS SDK?
The closest you can get to speech recognition is by using the UIDictationPhrase, which is a part of the UITextInput Protocol. However bear in mind that this API is available since iOS 5.1.