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. 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






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






3. 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






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






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






6. More aggressive lossy data reduction techniques that require further manipulation of the stereo field; Examples are 'Intensity' & 'M-S'






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






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






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






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






11. 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






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






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






14. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






15. 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






16. Method of representing an acoustic quantity with a series of binary numbers; Can have only specific individually distinct values






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






18. Process that begins with a fast FFT analysis of the spectra of two input signals - then the multiplication of like frequencies - and IFFT to finalize the process






19. Single- pin RCA cable or fiber- optic TOSLINK connector used for digital transfer; 75O coaxial - 2- channel unbalanced; 'Consumer' format of AES3






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






21. ABR; Codecs that encode data by determining how dense or sparse areas of the audio are while also keeping bit rate within specified limits to avoid rebuffering






22. DAW's and software must buffer when converting or bouncing and this latency can add up if not monitored






23. Measure of the amplitude of a longitudinal wave






24. 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






25. Discrete incremental distinctions made between the value of one sample and the next; Breaks down bit depth into a series of evenly spaced intervals






26. 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






27. 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






28. 8.75 GB; DS/SL






29. 4.38 GB; SS/SL






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






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






32. 'Reconstructing' part of digital audio






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






34. 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






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






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






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






38. EBU






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






40. The loudest point of a Full Scale system






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






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






43. Lossless Format; Can hold up to 25GB on a single- layer disc and 50GB on a dual- layer disc






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






45. 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






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






47. 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






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






49. The number of compressions or rarefactions in one second; The higher the frequency the more compressions & rarefactions per second; Measured in Hertz






50. 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.