Beamforming and Microphone Arrays Quiz

Answers and explanations appear as you take the quiz.

1. What physical cue does beamforming primarily exploit?
   • Time/phase differences of arrival across multiple microphones
   • Color of the sound source
   • The battery level of the device
   • The temperature of the room
2. What is the simplest beamforming technique called?
   • Fourier folding
   • Delay-and-sum
   • Spectral gating
   • Pitch tracking
3. What is the defining constraint in an MVDR beamformer?
   • Maximize every incoming direction equally
   • Remove the desired source before summation
   • Preserve the desired target response while minimizing output power
   • Convert the microphone signals into text
4. How does beamforming relate to single-microphone noise suppression?
   • It fully replaces it and makes it obsolete
   • It is identical to it
   • It only works without any other processing
   • It complements it by adding spatial information a single mic lacks
5. Why can microphone spacing that is too large create spatial aliasing?
   • Different directions can produce indistinguishable sampled phase differences at a frequency
   • The microphones stop recording sound
   • The sample rate automatically drops to zero
   • The array loses all time information
6. What is 'neural beamforming'?
   • Beamforming done entirely by hand
   • Combining deep networks (e.g., mask or direction estimation) with the spatial beamformer
   • Removing all microphones
   • A type of single-channel pitch shifter
7. What can happen when an MVDR beamformer’s assumed steering vector is inaccurate?
   • The array automatically gains microphones
   • The audio changes into a spectrogram image
   • Its target preservation or interference suppression can degrade
   • The desired source is always amplified without limit
8. What information determines the steering delays for a chosen look direction?
   • Audio file format and transcript length
   • Speaker age and language
   • The number of model parameters alone
   • Target direction, microphone geometry, and speed of sound