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. Method of sampling data at a higher resolution (higher sample rate) as a means of reducing harmonic content during D/A conversion; (x2) oversampling gets rid of all odd harmonic content






2. Reduces the percieved distortion due to quantization error; Low level white noise source is introduced to make the profile of the quantization 'noise' more irregular; Useful when reducing the number of bits per word in a signal (i.e. when converting






3. 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






4. Used as the main disc from which other discs are made; Composed of ground glass with a very fine photoresistor layer; An imaging laser burns pit and land patterns in preparation for duplication






5. 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






6. Level above which audible sounds are painful (125 - 130 db)






7. Six channel (five speakers and one subwoofer for bass) digital surround sound system by Dolby






8. Specific set of instructions for carrying out a data reduction technique that determines how to 'save' binary data information efficiently






9. 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)






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






11. Measure of the amplitude of a longitudinal wave






12. Data is transmitted over fiber optic lines; Uses a TOSLINK connecter instead of an RCA type; Can transmit multi- channel audio; Not susceptible to ground hum and loops; Able to support far higher rates of data transfer over greater distances than coa






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






14. Ratio of magnitude of the analytical signal to the magnitude of the background noise signal






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






16. 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






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






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






19. 1st commercially successful AoE format for the transmission of digital audio - video - and control signals over 64- channel 100Mbps Ethernet networks






20. Only 2 digits used; The value of each place (ones - hundreds - etc.) are as follows from greatest to least: 128 - 64 - 32 - 16 - 8 - 4 - 2 - 1






21. Smallest interval measurable by a scientific instrument; Defined by bit rate (sample rate x bit depth)






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






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






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






25. 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






26. The art of deciding where to place a processor in signal flow based on how that processor will be influenced by the other processors in the path






27. Amplitude meter that takes the square root of all instantaneous amplitudes and averages them to find a mean and squares that value; Useful with particularly complex waveforms






28. 7.95 GB; SS/DL






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






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






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






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






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






34. EBU






35. Root Mean Square; Refers to taking the square root of all instantaneous amplitudes; Takes the average of those squares; (-6 Peak Level is approximately equal to -20 RMS)






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






37. 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






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






39. 8- in/8- out on one cable; 25- pin D- sub connector






40. Process of building a complex tone by starting with the fundamental frequency and adding pure tone harmonics






41. Eight channel digital surround sound system by Dolby






42. How Loud (Y-Axis) & How Fast (X-Axis)






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






44. Contains all even and odd harmonics associated with a fundamental tone - making it a rich source for modeling other sounds; Amplitude of each overtone decreases exponentially as a ratio of the harmonic's frequency to that of the fundamental






45. (AES/EBU); 110O - 2- channel balanced digital audio cable with an XLR connection; NOT a mic cable!!






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






47. The process of reducing the space required to store data by efficiently encoding the content.






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






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






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