     {
         let description = "Transcribe an audio file."
         let expectation = self.expectation(description: description)
+        var expectationFulfilled = false
         
         let bundle = Bundle(for: type(of: self))
         guard let file = bundle.url(forResource: filename, withExtension: withExtension) else {

            settings.timestamps = true
            settings.filterProfanity = false
            settings.speakerLabels = true
            
            speechToText.recognize(audio: audio, settings: settings, model: "en-US_NarrowbandModel", learningOptOut: true, failure: failWithError) { results in
                self.validateSTTSpeakerLabels(speakerLabels: results.speakerLabels)
                expectation.fulfill()
            }
            waitForExpectations()
        } catch {

    }
    
    func validateSTTSpeakerLabels(speakerLabels: [SpeakerLabel]) {
        XCTAssertGreaterThan(speakerLabels.count, 0)
        for speakerLabel in speakerLabels {
            validateSTTSpeakerLabel(speakerLabel: speakerLabel)
        }
