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. MPEG; Standardizing body of audio coding






3. Roughly around 1 -130 ft/s






4. Amplitude meter that takes the square root of all instantaneous amplitudes and averages them to find a mean and squares that value; Useful with particularly complex waveforms






5. Inner ear component that attaches to the stapes and helps to decrease the amplitude of vibrations; Causes the masking phenomenon






6. EBU






7. 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






8. 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






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






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






11. 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






12. Sample Rate x Bit Depth x # of Channels






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






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






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






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






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






18. Signal conversions are mixed with playback tracks resulting in near-zero latency






19. 'Reconstructing' part of digital audio






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






21. (Time Based) Frequency: Aliasing; Anti-Aliasing Filter; Sample Rate; Nyquist Limit






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






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






24. 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






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






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






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






28. 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






29. 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)






30. Increases or decreases the digital signal so that the loudest sample is brought up to 0dBfs; Uses all bits from dynamic range and makes it even from track to track






31. French mathematician that noted that any complex sound can be broken down into a series of component pure tones






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






33. 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






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






35. Fractional part of a floating- point number; Also called the mantissa; Defines precision






36. The loudest point of a Full Scale system






37. 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






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






39. 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






40. Reduces A/D sample rate from the oversampled rate to nominal rate by turning series of one- bit samples into a series of multi- bit PCM samples; (ex. => 2.8MHz sample rate converted to 44.1kHz and simultaneously converts 1-Bit samples to multi- bit);






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






42. The mathematics - algorithms - and the techniques used to manipulate signals after they have been converted to digital form






43. 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






44. 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






45. 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






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






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






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






49. 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)






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