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. 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)






2. Only 2 digits used; The value of each place (ones - hundreds - etc.) are as follows from greatest to least: 128 - 64 - 32 - 16 - 8 - 4 - 2 - 1






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






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






5. 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






6. Same as 'aliasing'






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






8. Sample Rate x Bit Depth x # of Channels






9. Six channel (five speakers and one subwoofer for bass) digital surround sound system by Dolby






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






11. MPEG; Standardizing body of audio coding






12. 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)






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






14. 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






15. 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






16. 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






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






18. Sony sigma- delta modulation based technology that bypasses the decimation and interpolation steps found in PCM converters






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






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






21. 1st commercially successful AoE format for the transmission of digital audio - video - and control signals over 64- channel 100Mbps Ethernet networks






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






23. The amount of energy at each wavelength






24. 12.33 GB; DS/ML






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






26. Circuit that interprets the meaning of the symbols as they were chosen and arranged by the encode






27. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






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






29. Allowance of noise floor below that which is required for the final product






30. 'Reconstructing' part of digital audio






31. The difference in volume between the loudest and quietest sounds of a source






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






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






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






35. Method used in digital recording and reproduction in which a signal is sampled at various points and the resulting value is translated into binary numbers






36. Data is transmitted over fiber optic lines; Uses a TOSLINK connecter instead of an RCA type; Can transmit multi- channel audio; Not susceptible to ground hum and loops; Able to support far higher rates of data transfer over greater distances than coa






37. 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.






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






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






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






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






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






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






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






45. The loudest point of a Full Scale system






46. EBU






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






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






49. 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






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