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. Same as 'aliasing'






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






3. The art of deciding where to place a processor in signal flow based on how that processor will be influenced by the other processors in the path






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






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






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






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






8. AES






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






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






11. 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






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






13. 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.






14. 8.75 GB; DS/SL






15. Anytime bit depth is reduced the gap gets bigger so more dithering is required






16. 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






17. 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






18. 4.38 GB; SS/SL






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






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






21. 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






22. 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






23. 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






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






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. 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






27. Measure of the amplitude of a longitudinal wave






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






29. Take up half as many bits (50%); Algorithm can keep same quality by lossing the stereo track






30. 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






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






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






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






34. Decibels Full Scale






35. 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






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






37. Based on Full Scale (dB/FS); -6dB represents a loss of one bit so account for this when calculating






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






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






40. In order to play multiple channels at one time data is buffered as read to disk; Latency happens between play command & beginning of playback






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






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






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






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






45. Sample Rate x Bit Depth x # of Channels






46. Eight channel digital surround sound system by Dolby






47. 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);






48. Waveform of a pure tone showing simple harmonic motion






49. 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






50. If a signal is sampled at a rate higher than twice the highest significant signal frequency and at evenly spaced intervals - then the samples contain all the information of the original signal