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






2. Subtract place values from the decimal number and place ones or zeros in the correct places






3. The frequency range that is allowed through a filter






4. EDL; Final list of samples used in the audio editing process; Identified by time code






5. More aggressive lossy data reduction techniques that require further manipulation of the stereo field; Examples are 'Intensity' & 'M-S'






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






7. 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






8. 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






9. 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






10. Circuit that seizes voltage values with each tick of an A/D device's internal clock






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






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






13. 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.






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






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






16. 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






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






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






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






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






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






22. 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






23. 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






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






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






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






27. 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






28. Level above which audible sounds are painful (125 - 130 db)






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






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






32. The process of reducing the space required to store data by efficiently encoding the content.






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






34. 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






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






36. The continuous loss of signal strengths as a signal travels through a medium






37. Process that begins with a fast FFT analysis of the spectra of two input signals - then the multiplication of like frequencies - and IFFT to finalize the process






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






39. 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






40. 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)






41. Perceptual coding technique that uses louder sounds of a similar frequency to decide what information is to be saved during data reduction






42. Discrete incremental distinctions made between the value of one sample and the next; Breaks down bit depth into a series of evenly spaced intervals






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






44. 8.75 GB; DS/SL






45. 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






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






47. The act of a frequency swinging back and forth with a steady - uninterrupted rhythm






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






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






50. AES