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. 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






2. 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)






3. Represents the amplitude component of the digital sampling process; Technique of incrementing a continuous analog event into a discrete set of binary digits (bits)






4. 4.38 GB; SS/SL






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






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






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






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






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






10. A method of representing real numbers using a mantissa and an exponent






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






12. 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






13. 1.) Taking a series of evenly- spaced measurements 2.) Signal contains no frequency components higher than half the sample rate






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






15. Used when the reference pressure of a sound is 20 microPa (0.00002); Sound Pressure Level; Measure of amplitude






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






17. 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)






18. Digital (binary) measurements of how long each pulse is either on or off; Width of increasing voltage or decreasing voltage is assigned a 1 or 0 respectively






19. AAC (Advanced Audio Coding); MP3; RA; WMA; OGG Vorbis; Dolby Digital/AC-3; DTS; ADPCM






20. 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.






21. 8.75 GB; DS/SL






22. Built into DAWs; Bits are added when signals are mixed together to avoid clipping






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






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






25. 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






26. The loudest point of a Full Scale system






27. In order to play multiple channels at one time data is buffered as read to disk; Latency happens between play command & beginning of playback






28. 'Reconstructing' part of digital audio






29. Algorithm uses matrix of a mid/side microphone pair to determine a side signal & that signal is reduced then distributed as code in stereo






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






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






32. 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.






33. Stores only one copy of a stereo signal and assigns it to both channels in order to save 50% of original bandwidth






34. Sample Rate x Bit Depth x # of Channels






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






36. 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






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






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






39. Allows for an internal sample rate at multiples of the input and output rates; Alleviates the need for steep 'brickwall' filters; Often combined with internal '1- bit' processing; Increases smoothing effect






40. HD Audio format; Lossless Compression; 24- bit/96 kHz; 5.1 Surround or 24- bit / 192 kHz stereo sound






41. High Pressure - Part of a longitudinal wave where the particles of the medium are close together






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






43. 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






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






45. Very quiet digital amplifier that produces a series of output pulses with the audio signal coded the same as the width of the output pulses; Pulses are used to represent wave forms and are either on or off; Intense signals have long pulses with short






46. Occurs as data is assembled into meaningful bits or information and as left & right channels are separated






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






48. Digital and analog processing capability is combined on a single microchip allowing for 1- bit resolution at high sample rates






49. A sample- by- sample operation on two signals






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