Pitch Shifting and Time Stretching Quiz

Answers and explanations appear as you take the quiz.

1. During pitch shifting, which property should change while duration remains stable?
   • Change duration while preserving pitch
   • Change loudness while preserving both
   • Change perceived pitch while preserving duration
   • Convert stereo audio to mono
2. During time stretching, which property should change while pitch remains stable?
   • Change pitch while preserving duration
   • Change duration while preserving pitch
   • Remove all transients
   • Change only the sample-rate metadata
3. What happens when playback rate is changed directly without compensation?
   • Only pitch changes
   • Only duration changes
   • Neither changes
   • Duration and pitch both change
4. Which representation does a conventional phase-vocoder implementation modify?
   • Short-time Fourier transform domain
   • A text-token sequence from a speech recognizer
   • A pitch-class histogram with all phase discarded
   • An unframed average power spectrum with no time information
5. Which signal can expose transient smearing in a phase vocoder?
   • A long steady sinusoid without a transient onset in the evaluated region
   • A slowly varying sustained tone
   • Percussive audio with sharp attacks
   • A stationary segment whose amplitude and frequency remain constant
6. What does PSOLA rely on for voiced speech processing?
   • An arbitrary frame grid unrelated to voicing
   • Pitch-synchronous marks or periods
   • Only the transcript's word boundaries
   • Only the average spectrum of the whole recording
7. During ordinary sample-rate conversion, what happens when the output sample rate is correctly updated to represent the same signal?
   • Pitch necessarily rises at every new sample rate
   • Duration always halves during any rate conversion
   • Pitch must change even when the output represents the same time span
   • Pitch and duration are preserved rather than intentionally shifted
8. How should an audio augmentation transformation be chosen?
   • Keep changes plausible and preserve the task label
   • Use the largest possible stretch
   • Apply it to test data until results improve
   • Choose a method without listening