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






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






3. 7.95 GB; SS/DL






4. 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






5. The loudest point of a Full Scale system






6. Defines the number of sample per second taken from a continuous signal to make a discrete signal; Governs the frequency response of digital audio






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






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






9. Reference voltage determined by summing the voltage values of a predetermined number of previous samples; Numbers of 1 in row = waveform peak; Numbers of 0 in row = waveform trough; Basis of Sony's Direct Stream Digital (DSD)






10. 12.33 GB; DS/ML






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






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






13. The amount of energy at each wavelength






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






15. AES






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






17. Also known as equal loudness curves; Graph that indicates the average ear sensitivity to different frequencies at different SPL levels (as volume increases - these curves flatten out)






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






19. 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






20. 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






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






23. 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






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






25. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






26. Have odd numbered harmonics






27. How Loud (Y-Axis) & How Fast (X-Axis)






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






29. MPEG; Standardizing body of audio coding






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






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






32. 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






33. Measure of the amplitude of a longitudinal wave






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






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






36. EBU






37. Waveform of a pure tone showing simple harmonic motion






38. 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






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






40. 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






41. 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






42. Visual graph that shows how loud a sound is at different frequencies






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






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






45. 8.75 GB; DS/SL






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






47. A time regulator that makes all samples and bits to align when working with interconnected digital devices; Basically a signal that all of the digital devices refer to when operating.






48. 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






49. 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






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