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. 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






2. 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






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






4. Toshiba developed digital audio interface utilizes fiber optics as a transmission medium.






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






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






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






8. Measures the highest levels of a signal being recorded or mixed; Monitors for clipping - which occurs at 0dBFS); Does not always reflect perceived volume of signal






9. 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






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






11. 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






12. 8- in/8- out on one cable; 25- pin D- sub connector






13. Overtones that contribute to the timbre of a sound and make up a complex waveform's physical characteristics






14. Same as 'aliasing'






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






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






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






18. Measure of sound pressure over the frequency spectrum - for which a listener perceives a constant loudness when presented with pure steady tones






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






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






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






22. AES






23. Samples are duplicated and the playback sampling rate correspondingly increased; Significantly raises the Nyquist limit to a range well beyond human hearing; Processing 'pushes' the distortion resulting from quantization error into these higher frequ






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






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






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






27. 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






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. Sample Rate x Bit Depth x # of Channels






30. 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






31. Ultra low- latency - 512- channel (on a gigabit network) - less flexible AoE format; Routed like audio cables...not network cables






32. 7.95 GB; SS/DL






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






34. Roughly around 1 -130 ft/s






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






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






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






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






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






40. Mixing data and control characters in a single operation






41. A digital filter's time domain output sequence when the input is a single sample is input






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






43. 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






44. 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






45. 'Reconstructing' part of digital audio






46. 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






47. 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






48. 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






49. Subtract place values from the decimal number and place ones or zeros in the correct places






50. 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