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. Describes acceptable data - performances both offered and essential for a disc player - and the complete user experience






2. 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






3. 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






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






5. The set of rules that computers use to move files from one computer to another on an internet






6. CBR; Codecs encodes data at a constant rate regardless of density of the audio file






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






8. 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






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






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






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






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






13. The loudest point of a Full Scale system






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






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






16. 1.) Bit Rate x Sample Rate (you'll get b/sec) 2.) Multiply by 60 if converting seconds to minutes 3.) Divide by 8 to convert bits to Bytes and get B/min 4.) Divide by 1 -024 to get KB/min and keep doing it until you get desired bit rate specification






17. 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.






18. 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






19. Have odd numbered harmonics






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






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






22. 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






23. The amount of energy at each wavelength






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






25. 1st commercially successful AoE format for the transmission of digital audio - video - and control signals over 64- channel 100Mbps Ethernet networks






26. EBU






27. Take up half as many bits (50%); Algorithm can keep same quality by lossing the stereo track






28. Voltage -> Dither -> Anti-Aliasing (Low Pass Filter) -> Sample & Hold Circuit -> Successive Approximation/Quantizer --) 100111010 (PCM Audio File)






29. 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






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






31. Having a repeated succession of waves or curves as in a sound waveform






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






33. 8- in/8- out on one cable; 25- pin D- sub connector






34. 15.9 GB; DS/DL






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






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






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






38. Softest sound that can be heard by the average human ear (0 dB)






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






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






41. Snippets of time in which frequency analysis takes place in a perceptual codec






42. 16-Bit; 44.1 kHz; PCM; Stereo






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






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






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






46. 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






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






48. 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






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






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