Sorry to hear that. I haven’t ever heard of that as an issue so I think it is likely to be a missed step from the initial process of adding the framework. AcousticModel is a class from the main distribution, so if it can’t be found it means that the framework isn’t linked. I would start with a clean project and pay special attention to these parts:
Make absolutely sure that in the add dialog “Create groups for any added folders” is selected and NOT “Create folder references for any added folders” because the wrong setting here will prevent your app from working.
If you are using Xcode 5 with a build number of 5A1413 or later, it has a bug which results in frameworks linked by reference being changed to link at incorrect URL paths, so it is necessary for you to also check the box that says “Copy items into destination group’s folder (if needed)”, or you may receive errors that header files can’t be found. If you receive this kind of error with Xcode 5, it means that your Framework Search Path for the added frameworks has been changed to an invalid URL, so you may have to open that Build Setting for your app target and change it back to a correct path.
If this doesn’t clear it up, please feel free to copy and paste the entire error so I can take a look. There will be a disclosure bubble in the build log that will let you copy and paste the complete error (the part above is just an excerpt).