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. 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.






2. Psychoacoustic model of data reduction used for general audio compression that aims to transmit only features perceptible to the human ear; Useful for mastering streaming media






3. 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






4. 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






5. Roughly around 1 -130 ft/s






6. 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






7. 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






8. 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






9. 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






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






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






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






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






15. 16-Bit; 44.1 kHz; PCM; Stereo






16. Leaving space at beginning and ending of song for data crunching during mastering; Last step in mastering process






17. The frequency range that is allowed through a filter






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






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






20. 12.33 GB; DS/ML






21. 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)






22. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






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






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






25. 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






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






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






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






29. MPEG; Standardizing body of audio coding






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






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






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






33. 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






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






35. 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






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






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






38. Softest sound that can be heard by the average human ear (0 dB)






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






40. Number or variable that represents the number of times the base of a power is used as a factor; Defines magnitude






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






42. (AES/EBU); 110O - 2- channel balanced digital audio cable with an XLR connection; NOT a mic cable!!






43. Eight channel digital surround sound system by Dolby






44. Data transmission protocol over which computer network traffic travels; Poorly suited to real- time transmission but numerous attempts have been made to harness the technology because of its flexible routing; Uses simple Cat5 cabling; Resists interfe






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






46. Mixing data and control characters in a single operation






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






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






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






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