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. 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






2. CobraNet; EtherSound; Dante; AVB (currently under development)






3. 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






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






5. 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.






6. 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






7. 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






8. Specific set of instructions for carrying out a data reduction technique that determines how to 'save' binary data information efficiently






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






10. 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






11. Six channel (five speakers and one subwoofer for bass) digital surround sound system by Dolby






12. AES






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






14. Accuracy with which an electronic system reproduces the sound or image of its input signal






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






16. 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






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






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






19. 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






20. ADAT Optcal; 8- in/8- out on two cables; Fiber- optic - TOSLINK connector






21. Apple Lossless; Windows Media Lossless; DTS HD Master Audio; Dolby True HD; FLAC






22. Sum of all harmonics; Sum of sine and cosine waves which have frequencies f - 2f - 3f - 4f...






23. 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






24. 7.95 GB; SS/DL






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






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






27. A network communications protocol that specifies how machines will exchange data; Uses a broadcast system in which one machine transmits its message on the communication medium and the other machines listen for messages directed to them






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






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






30. Only 2 digits used; The value of each place (ones - hundreds - etc.) are as follows from greatest to least: 128 - 64 - 32 - 16 - 8 - 4 - 2 - 1






31. Measure of the amplitude of a longitudinal wave






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






33. Measure of sound pressure over the frequency spectrum - for which a listener perceives a constant loudness when presented with pure steady tones






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






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






36. Algorithm uses matrix of a mid/side microphone pair to determine a side signal & that signal is reduced then distributed as code in stereo






37. Sample Rate x Bit Depth x # of Channels






38. ADPCM; Pulse code modulation that produces a digital signal with a lower bit rate than standard PCM; Records only the difference between samples






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






40. 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






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






42. 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






43. 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






44. 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)






45. Signal voltage is relayed to a register from sample- and - hold circuit; Holds reference frequencies in binary form that decrease in value; Finds approximated value & assigns binary number accordingly






46. EBU






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






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






49. Have odd numbered harmonics






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