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






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






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






4. Splits the input signal and mixes it with an analog copy so that no latency is present






5. Reference voltage determined by summing the voltage values of a predetermined number of previous samples; Numbers of 1 in row = waveform peak; Numbers of 0 in row = waveform trough; Basis of Sony's Direct Stream Digital (DSD)






6. Difference in brightness between land and pit on a CD Physical Format






7. As sample rate is increased more room is created for a smoother slope of the attenuation band because Nyquist limit extends well beyond range of hearing with each increase






8. 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






9. More accuracy in low amplitudes and less in higher amplitudes






10. VBR; Most common & best data reduction technique; Codecs that encode data by determining how dense or sparse areas of the audio are; Can result in buffering issues






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






12. 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






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






14. 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)






15. Rate at which energy is drawn from a source that produces a flow of electricity in a circuit; Expressed in volts






16. 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






17. Mixing data and control characters in a single operation






18. Visual graph that shows how loud a sound is at different frequencies






19. Circuit that seizes voltage values with each tick of an A/D device's internal clock






20. Series of dots and dashes representing the letters of the alphabet; Most common letters are represented by the shortest dots and dashes; Example of entropy coding






21. 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






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






23. 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






24. Most significant lossless coding technique in current use; Measure of disorder in which long strings of data are represented by short symbols and uses the shortest symbols to represent the most common repetitive audio data maximizing data reduction






25. A drive that can read and write on optical media that hold up to 50 GB on two layers; 24- bit/96 kHz for 8-Channel; 24- bit/192 kHz for 6-Channel






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






27. EBU






28. 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






29. Branch of psychology concerned with the subjective perception of sound






30. Very selective method of lowering buffer levels by halting different levels of audio processing






31. Increases D/A sample rate from nominal rate to oversampling rate by turning series multi- bit PCM samples into 1- bit samples; (ex. => 44.1kHz sample rate converted to 2.8MHz and simultaneously converts multi- bit samples to 1- bit); Low Pass Filter






32. Describes various optical disc characteristics including the size and shape of the disc - the size of pits - the speed at which the disc spins - and a multitude of aspects regarding the specifications of the player itself






33. Full Scale; Type of metering that measures level in digital recording system; Recording and Mixing levels should NEVER exceed 0dB FS in digital audio or clipping will occur






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






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






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






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






38. Low Pressure; Part in a longitudinal wave where the particles are spread apart






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






40. (Amplitude Based) Amplitude: Voltage; Quantization; Bit Depth; Quantization Intervals; Quantization Noise; [Signal:Quantization Noise Ratio]; Dither; Dynamic Range






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






42. 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






43. Twice as many samples as the highest frequency at minimum; Sampling rate totally controls frequency response






44. Sample Rate x Bit Depth x # of Channels






45. 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)






46. Decibels Full Scale






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






48. Playback; I/O Connections; CPU (Streaming); Conversion from DAW or Software






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






50. 7.95 GB; SS/DL