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






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






3. 4.38 GB; SS/SL






4. 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






5. The ability of a digital system to perform complex DSP without running into problems with overflow or loss of resolution






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






7. 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






8. Ratio of magnitude of the analytical signal to the magnitude of the background noise signal






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






10. 8.75 GB; DS/SL






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






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






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






14. 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






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






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






17. Data is transmitted over fiber optic lines; Uses a TOSLINK connecter instead of an RCA type; Can transmit multi- channel audio; Not susceptible to ground hum and loops; Able to support far higher rates of data transfer over greater distances than coa






18. 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






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






20. Unit of measurement that is equal to one millionth of a meter






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






22. Digital Word -> Series of Resistors (each with assigned charges) -> Sample- and-Hold Circuit -> Anti-Imaging Filter (Smoothing Filter) -> Reconstructed Sample






23. HD Audio format; Lossless Compression; 24- bit/96 kHz; 5.1 Surround or 24- bit / 192 kHz stereo sound






24. 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);






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






26. 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






27. Roughly around 1 -130 ft/s






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






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






30. 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)






31. The amount of energy at each wavelength






32. 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)






33. Most significant lossless coding technique in current use; Measure of disorder in which long strings of data are represented by short symbols and uses the shortest symbols to represent the most common repetitive audio data maximizing data reduction






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






35. 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






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






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






38. 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






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






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






41. The elapsed time it takes for a packet of data to arrive at its destination; Lagging or pause of an audio signal as digital processing occurs; Can be managed utilizing several forms of 'audio monitoring'






42. MPEG; Standardizing body of audio coding






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






44. Uses entropy coding as the basis; Computer data compression algorithm that packages files such as .ZIP & .RAR






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






46. 7.95 GB; SS/DL






47. 8- in/8- out on one cable; 25- pin D- sub connector






48. 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






49. 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.






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