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. Describes acceptable data - performances both offered and essential for a disc player - and the complete user experience






2. 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






3. 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)






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






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






6. EBU






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






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






10. 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






11. 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);






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






13. 15.9 GB; DS/DL






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






15. Mixing data and control characters in a single operation






16. French mathematician that noted that any complex sound can be broken down into a series of component pure tones






17. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






18. 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






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






20. 7.95 GB; SS/DL






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






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






23. 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






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






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






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






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






28. 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






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






30. Used when the reference pressure of a sound is 20 microPa (0.00002); Sound Pressure Level; Measure of amplitude






31. Branch of psychology concerned with the subjective perception of sound






32. The more bits allocated during quantization - the more accurate the measurement






33. 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.






34. 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






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






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






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






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






39. If a signal is sampled at a rate higher than twice the highest significant signal frequency and at evenly spaced intervals - then the samples contain all the information of the original signal






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






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






42. 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






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






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






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






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






47. 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






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






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






50. (Amplitude Based) Amplitude: Voltage; Quantization; Bit Depth; Quantization Intervals; Quantization Noise; [Signal:Quantization Noise Ratio]; Dither; Dynamic Range