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. The loudest point of a Full Scale system






2. 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






3. 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






4. A sample- by- sample operation on two signals






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






6. 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






7. Occurs as data is assembled into meaningful bits or information and as left & right channels are separated






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






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






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






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






12. Describes various optical disc characteristics including the size and shape of the disc - the size of pits - the speed at which the disc spins - and a multitude of aspects regarding the specifications of the player itself






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. 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






15. Multi-Bit Words; (Pulse Code Modulation)






16. 16-Bit; 44.1 kHz; PCM; Stereo






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






18. Electromagnetic receptor that detects the radiation known as visible light






19. Unit of measurement that is equal to one billionth of a meter






20. 12.33 GB; DS/ML






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






22. Number or variable that represents the number of times the base of a power is used as a factor; Defines magnitude






23. Sample Rate x Bit Depth x # of Channels






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






25. Stores only one copy of a stereo signal and assigns it to both channels in order to save 50% of original bandwidth






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






27. Channels are processed one at a time and the results are stored on multiple CPU buffers that alternately send data as DAW requests the data for playback; First few seconds are relayed to the buffer prior to processing and playback and it continuously






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






29. 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);






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






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. Mixing data and control characters in a single operation






33. 7.95 GB; SS/DL






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






35. 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.






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






37. AES






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






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






40. Digital and analog processing capability is combined on a single microchip allowing for 1- bit resolution at high sample rates






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






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






43. 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






44. Have odd numbered harmonics






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






46. 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






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






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






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






50. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits