Test your basic knowledge |

Digital Audio

Subject : engineering
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Waveform of a pure tone showing simple harmonic motion






2. Take up half as many bits (50%); Algorithm can keep same quality by lossing the stereo track






3. A situation where a calculated value cannot fit into the number of digits reserved for it






4. Industry Standards: -6 dB Peak = -20 RMS Meter






5. Data reduction technique that does not effect quality of original audio; No effect on original quality; Typically around 50% reduction; Exact reconstruction of digital code for the audio signal






6. Signal that uses variable voltage to create continuous waves resulting in an inexact transmission






7. Governs the frequency response of a digital system; The highest- frequency component that can be captured with a sampling rate; always 1/2 of sampling rate; Also called the limiting frequency






8. 4.38 GB; SS/SL






9. The act of a frequency swinging back and forth with a steady - uninterrupted rhythm






10. EDL; Final list of samples used in the audio editing process; Identified by time code






11. Pertaining to hearing or sound; Combination of the intensity of air pressure molecules with amplitude






12. Psychoacoustic model of data reduction used for general audio compression that aims to transmit only features perceptible to the human ear; Useful for mastering streaming media






13. 16-Bit; 44.1 kHz; PCM; Stereo






14. Accuracy with which an electronic system reproduces the sound or image of its input signal






15. Serial Copy Management System; main difference between AES3 & S/PIDF






16. The more bits allocated during quantization - the more accurate the measurement






17. Joint-Stereo Technique; Since the human brain is unable to localize sounds at high frequencies well sounds above 9 kHz threshold are encoded in mono






18. The frequency above or below which attenuation begins in a filter circuit






19. ADAT Optcal; 8- in/8- out on two cables; Fiber- optic - TOSLINK connector






20. Inner ear component that attaches to the stapes and helps to decrease the amplitude of vibrations; Causes the masking phenomenon






21. Measure of the amplitude of a longitudinal wave






22. Fractional part of a floating- point number; Also called the mantissa; Defines precision






23. Computer program or device capable of encoding and/or decoding a digital data stream with the end result being a reduced file size






24. Based on psychoacoustics - these are the basis of frequency analysis for a perceptual codec;






25. CobraNet; EtherSound; Dante; AVB (currently under development)






26. Measuring equipment in A/D conversion that processes voltage and provides a value for that voltage






27. Electromagnetic receptor that detects the radiation known as visible light






28. Improper (false) sampling of high frequencies that cause much lower frequencies to be produced when the audio is reconstructed; Foldover happens at higher frequencies as harmonics reach levels that exceed the Nyquist limit.






29. Eliminates frequencies above the Nyquist limit from becoming samples; Occurs prior to quantization






30. 8.75 GB; DS/SL






31. Number of bits per second processed when sampling sound; (Sampling Rate x Bit Depth) = Resolution






32. Each bit in the bit depth is equal to a _____ increase in dynamic range






33. Deviation from a normal - steady pulse or tick of a clock that contributes to misrepresentation of a signal; Result of small timing irregularities that become magnified during the transmission of digital signals as the signals are passed from one dev






34. Sony sigma- delta modulation based technology that bypasses the decimation and interpolation steps found in PCM converters






35. Data reduction technique that selectively removes original information in order to significantly reduce the file size; Some data is lost; Files can be reduced up to 99% in size (90% with no perceived sound quality loss); Bit rate effects the perceive






36. Number of bits used to represent the smallest unit of information in an audio file; Greater bit depth = better quality audio






37. More aggressive lossy data reduction techniques that require further manipulation of the stereo field; Examples are 'Intensity' & 'M-S'






38. Digital Word -> Series of Resistors (each with assigned charges) -> Sample- and-Hold Circuit -> Anti-Imaging Filter (Smoothing Filter) -> Reconstructed Sample






39. Defines the number of sample per second taken from a continuous signal to make a discrete signal; Governs the frequency response of digital audio






40. Discrete incremental distinctions made between the value of one sample and the next; Breaks down bit depth into a series of evenly spaced intervals






41. Based on Full Scale (dB/FS); -6dB represents a loss of one bit so account for this when calculating






42. Unit of measurement that is equal to one millionth of a meter






43. ABR; Codecs that encode data by determining how dense or sparse areas of the audio are while also keeping bit rate within specified limits to avoid rebuffering






44. High channel count; 64 channels on one cable; Coaxial cable with BNC connector or fiber optic with ST1 connector






45. Channels are processed one at a time and the results are stored on multiple CPU buffers that alternately send data as DAW requests the data for playback; First few seconds are relayed to the buffer prior to processing and playback and it continuously






46. The amount of energy at each wavelength






47. Perceptual coding technique that uses louder sounds of a similar frequency to decide what information is to be saved during data reduction






48. Roughly around 1 -130 ft/s






49. The ability of a digital system to perform complex DSP without running into problems with overflow or loss of resolution






50. 12.33 GB; DS/ML