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. Allows for an internal sample rate at multiples of the input and output rates; Alleviates the need for steep 'brickwall' filters; Often combined with internal '1- bit' processing; Increases smoothing effect






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






4. Reduces the percieved distortion due to quantization error; Low level white noise source is introduced to make the profile of the quantization 'noise' more irregular; Useful when reducing the number of bits per word in a signal (i.e. when converting






5. Perceptual coding technique that uses louder sounds of a similar frequency to decide what information is to be saved during data reduction






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






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






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






9. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






10. Measures the highest levels of a signal being recorded or mixed; Monitors for clipping - which occurs at 0dBFS); Does not always reflect perceived volume of signal






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






12. 'Capturing' part of digital audio; Never captures a signal perfectly






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






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






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






16. 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.






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






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






19. 12.33 GB; DS/ML






20. Waveform of a pure tone showing simple harmonic motion






21. 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)






22. 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);






23. 1.) Taking a series of evenly- spaced measurements 2.) Signal contains no frequency components higher than half the sample rate






24. 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






25. 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






26. The difference between the analog value and the approximated digital value due to the 'rounding' that occurs while converting the analog signal to digital






27. 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






28. 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






29. Leaving space at beginning and ending of song for data crunching during mastering; Last step in mastering process






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






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






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






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






34. Subtract place values from the decimal number and place ones or zeros in the correct places






35. A method of representing real numbers using a mantissa and an exponent






36. 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






37. Same as 'aliasing'






38. 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






39. Have odd numbered harmonics






40. Twice as many samples as the highest frequency at minimum; Sampling rate totally controls frequency response






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






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






43. 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






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






45. 15.9 GB; DS/DL






46. 4.38 GB; SS/SL






47. The more bits allocated during quantization - the more accurate the measurement






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






49. 8- in/8- out on one cable; 25- pin D- sub connector






50. CobraNet; EtherSound; Dante; AVB (currently under development)