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






2. 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






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






4. ABR; Codecs that encode data by determining how dense or sparse areas of the audio are while also keeping bit rate within specified limits to avoid rebuffering






5. Based on psychoacoustics - these are the basis of frequency analysis for a perceptual codec;






6. 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






7. 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






8. 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






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






10. 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






11. The frequency above or below which attenuation begins in a filter circuit






12. Single- pin RCA cable or fiber- optic TOSLINK connector used for digital transfer; 75O coaxial - 2- channel unbalanced; 'Consumer' format of AES3






13. 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






14. Contains all even and odd harmonics associated with a fundamental tone - making it a rich source for modeling other sounds; Amplitude of each overtone decreases exponentially as a ratio of the harmonic's frequency to that of the fundamental






15. 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






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






17. 8- in/8- out on one cable; 25- pin D- sub connector






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






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






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






21. A digital filter's time domain output sequence when the input is a single sample is input






22. AAC (Advanced Audio Coding); MP3; RA; WMA; OGG Vorbis; Dolby Digital/AC-3; DTS; ADPCM






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






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






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






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






27. 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






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






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






30. Ultra low- latency - 512- channel (on a gigabit network) - less flexible AoE format; Routed like audio cables...not network cables






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






32. 8.75 GB; DS/SL






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






34. 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






35. DAW's and software must buffer when converting or bouncing and this latency can add up if not monitored






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






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






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






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






40. 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.






41. 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






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






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






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






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






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






47. The mathematics - algorithms - and the techniques used to manipulate signals after they have been converted to digital form






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






49. 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.






50. Sample Rate x Bit Depth x # of Channels