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. 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






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






3. Cable used to transmit data; Inner cable is surrounded by a plastic insulator - which is surrounded by a wire mesh conductor that insulates the internal signal wire from external interference and an outer casing that functions as a ground






4. Same as 'aliasing'






5. The number of compressions or rarefactions in one second; The higher the frequency the more compressions & rarefactions per second; Measured in Hertz






6. 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.






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






8. Sample Rate x Bit Depth x # of Channels






9. Circuit that interprets the meaning of the symbols as they were chosen and arranged by the encode






10. Single- pin RCA cable or fiber- optic TOSLINK connector used for digital transfer; 75O coaxial - 2- channel unbalanced; 'Consumer' format of AES3






11. Also known as equal loudness curves; Graph that indicates the average ear sensitivity to different frequencies at different SPL levels (as volume increases - these curves flatten out)






12. 'Capturing' part of digital audio; Never captures a signal perfectly






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






14. Sony and Philips optical disc format; Utilizes sigma delta DSD to offer higher resolution; 1- bit; 2.8224 MHz; 6-Channel






15. The continuous loss of signal strengths as a signal travels through a medium






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






17. Multi-Bit Words; (Pulse Code Modulation)






18. Leaving space at beginning and ending of song for data crunching during mastering; Last step in mastering process






19. If a signal is sampled at a rate higher than twice the highest significant signal frequency and at evenly spaced intervals - then the samples contain all the information of the original signal






20. A network communications protocol that specifies how machines will exchange data; Uses a broadcast system in which one machine transmits its message on the communication medium and the other machines listen for messages directed to them






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






22. Uses entropy coding as the basis; Computer data compression algorithm that packages files such as .ZIP & .RAR






23. Removes high frequency images and noise and smoothes the stair case output coming from of the sample and hold circuit; Also called a SMOOTHING FILTER






24. A time regulator that makes all samples and bits to align when working with interconnected digital devices; Basically a signal that all of the digital devices refer to when operating.






25. The elapsed time it takes for a packet of data to arrive at its destination; Lagging or pause of an audio signal as digital processing occurs; Can be managed utilizing several forms of 'audio monitoring'






26. Anytime bit depth is reduced the gap gets bigger so more dithering is required






27. Sum of all harmonics; Sum of sine and cosine waves which have frequencies f - 2f - 3f - 4f...






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






29. Signal conversions are mixed with playback tracks resulting in near-zero latency






30. Signal voltage is relayed to a register from sample- and - hold circuit; Holds reference frequencies in binary form that decrease in value; Finds approximated value & assigns binary number accordingly






31. The difference in volume between the loudest and quietest sounds of a source






32. Unit of measurement that is equal to one billionth of a meter






33. Method used in digital recording and reproduction in which a signal is sampled at various points and the resulting value is translated into binary numbers






34. The frequency range that is allowed through a filter






35. Data transmission protocol over which computer network traffic travels; Poorly suited to real- time transmission but numerous attempts have been made to harness the technology because of its flexible routing; Uses simple Cat5 cabling; Resists interfe






36. 16-Bit; 44.1 kHz; PCM; Stereo






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






38. Father of modern information theory; Solidified the Nyquist Theory by adding the concept that bits per second (binary representation of audio signals) must be at equal intervals to accurately represent data






39. The difference between the analog value and the approximated digital value due to the 'rounding' that occurs while converting the analog signal to digital






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






41. A frequency specified for a filter (digital or electronic) the marks the point at which the frequency content of a signal is altered +/- 3dB






42. 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






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






44. Number or variable that represents the number of times the base of a power is used as a factor; Defines magnitude






45. 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






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






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






48. ADPCM; Pulse code modulation that produces a digital signal with a lower bit rate than standard PCM; Records only the difference between samples






49. 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






50. When recording you want the smallest buffer available; When mixing you want the largest buffer available