According to the iOS docs, implementing
`- (id)insertDictationResultPlaceholder`

```Implementation of this method is optional but can be done when you want to provide a specific rectangle for the placeholder animation while the dictation results are being processed. ```

If you do not implement this method, UIKit will insert a default placeholder of 10 whitespace characters. By overriding this, no placeholder text will be inserted. If you implement the `insertDictationResultPlaceholder`, you must implement
`- (void)removeDictationResultPlaceholder:(id)placeholder willInsertResult:(BOOL)willInsertResult`