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. 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






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






3. Number of bits per second processed when sampling sound; (Sampling Rate x Bit Depth) = Resolution






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






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






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






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






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






9. 15.9 GB; DS/DL






10. 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






11. 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






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






13. 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






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






15. Difference in brightness between land and pit on a CD Physical Format






16. 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






17. Signal voltage is relayed to a register from sample- and - hold circuit; Holds reference frequencies in binary form that decrease in value; Finds approximated value & assigns binary number accordingly






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






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






20. The amount of energy at each wavelength






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






22. 7.95 GB; SS/DL






23. Digital Word -> Series of Resistors (each with assigned charges) -> Sample- and-Hold Circuit -> Anti-Imaging Filter (Smoothing Filter) -> Reconstructed Sample






24. 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






25. MPEG; Standardizing body of audio coding






26. 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






27. Measuring equipment in A/D conversion that processes voltage and provides a value for that voltage






28. Measurement at regular intervals of the amplitude of a varying waveform (in order to convert it to digital form); There must be a minimum of 2 samples for each cycle in a waveform






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






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






31. 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






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






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






34. Computer program or device capable of encoding and/or decoding a digital data stream with the end result being a reduced file size






35. Eight channel digital surround sound system by Dolby






36. 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






37. Waveform of a pure tone showing simple harmonic motion






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






39. 8.75 GB; DS/SL






40. Built into DAWs; Bits are added when signals are mixed together to avoid clipping






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






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






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






44. 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);






45. Splits the input signal and mixes it with an analog copy so that no latency is present






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






47. RAM holds in memory audio data before it is transferred to the memory controller; Certain amount of data is processed before large amounts of data are streamed to prevent latency






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






49. Found that aliasing was always a problem no matter how fast you sample; Less data recorded but more accurate; 2 samples per wave length.






50. Full Scale; Type of metering that measures level in digital recording system; Recording and Mixing levels should NEVER exceed 0dB FS in digital audio or clipping will occur