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. 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






2. 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






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






4. 'Reconstructing' part of digital audio






5. 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)






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






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






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






9. Industry Standards: -6 dB Peak = -20 RMS Meter






10. Overtones that contribute to the timbre of a sound and make up a complex waveform's physical characteristics






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






12. Playback; I/O Connections; CPU (Streaming); Conversion from DAW or Software






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






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






15. 1st commercially successful AoE format for the transmission of digital audio - video - and control signals over 64- channel 100Mbps Ethernet networks






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. The loudest point of a Full Scale system






18. Have odd numbered harmonics






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






20. 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






21. 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






22. 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






23. 15.9 GB; DS/DL






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






25. 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






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






27. 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






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






29. Low Pressure; Part in a longitudinal wave where the particles are spread apart






30. (Time Based) Frequency: Aliasing; Anti-Aliasing Filter; Sample Rate; Nyquist Limit






31. 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






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






33. Deviation from a normal - steady pulse or tick of a clock that contributes to misrepresentation of a signal; Result of small timing irregularities that become magnified during the transmission of digital signals as the signals are passed from one dev






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






35. More accuracy in low amplitudes and less in higher amplitudes






36. Process of building a complex tone by starting with the fundamental frequency and adding pure tone harmonics






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






38. Series of dots and dashes representing the letters of the alphabet; Most common letters are represented by the shortest dots and dashes; Example of entropy coding






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






40. 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






41. 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






42. Rate at which energy is drawn from a source that produces a flow of electricity in a circuit; Expressed in volts






43. When recording you want the smallest buffer available; When mixing you want the largest buffer available






44. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






45. Mixing data and control characters in a single operation






46. Very selective method of lowering buffer levels by halting different levels of audio processing






47. 1.) Taking a series of evenly- spaced measurements 2.) Signal contains no frequency components higher than half the sample rate






48. 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)






49. 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






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