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. Governs the frequency response of a digital system; The highest- frequency component that can be captured with a sampling rate; always 1/2 of sampling rate; Also called the limiting frequency






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






3. 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






4. Contains all even and odd harmonics associated with a fundamental tone - making it a rich source for modeling other sounds; Amplitude of each overtone decreases exponentially as a ratio of the harmonic's frequency to that of the fundamental






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






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






7. 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






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






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






10. 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






11. 15.9 GB; DS/DL






12. 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






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






14. 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






15. Increases D/A sample rate from nominal rate to oversampling rate by turning series multi- bit PCM samples into 1- bit samples; (ex. => 44.1kHz sample rate converted to 2.8MHz and simultaneously converts multi- bit samples to 1- bit); Low Pass Filter






16. Data reduction technique that selectively removes original information in order to significantly reduce the file size; Some data is lost; Files can be reduced up to 99% in size (90% with no perceived sound quality loss); Bit rate effects the perceive






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






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






19. 'Reconstructing' part of digital audio






20. The set of rules that computers use to move files from one computer to another on an internet






21. 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






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






23. 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)






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






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






26. Smallest interval measurable by a scientific instrument; Defined by bit rate (sample rate x bit depth)






27. 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






28. Waveform of a pure tone showing simple harmonic motion






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






30. 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






31. Samples are duplicated and the playback sampling rate correspondingly increased; Significantly raises the Nyquist limit to a range well beyond human hearing; Processing 'pushes' the distortion resulting from quantization error into these higher frequ






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






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






34. 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






35. The frequency range that is allowed through a filter






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






37. Decibels Full Scale






38. Signal that uses variable voltage to create continuous waves resulting in an inexact transmission






39. 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






40. 8.75 GB; DS/SL






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






42. A frequency specified for a filter (digital or electronic) the marks the point at which the frequency content of a signal is altered +/- 3dB






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






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






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






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






47. 7.95 GB; SS/DL






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






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






50. 8- in/8- out on one cable; 25- pin D- sub connector