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. 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






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






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






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






5. Allows for an internal sample rate at multiples of the input and output rates; Alleviates the need for steep 'brickwall' filters; Often combined with internal '1- bit' processing; Increases smoothing effect






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






7. 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






8. 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






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






10. 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






11. 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.






12. EBU






13. Splits the input signal and mixes it with an analog copy so that no latency is present






14. High channel count; 64 channels on one cable; Coaxial cable with BNC connector or fiber optic with ST1 connector






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






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






17. Anytime bit depth is reduced the gap gets bigger so more dithering is required






18. CBR; Codecs encodes data at a constant rate regardless of density of the audio file






19. Most significant lossless coding technique in current use; Measure of disorder in which long strings of data are represented by short symbols and uses the shortest symbols to represent the most common repetitive audio data maximizing data reduction






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






21. The loudest point of a Full Scale system






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






23. 7.95 GB; SS/DL






24. Sample Rate x Bit Depth x # of Channels






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






26. 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






27. Same as 'aliasing'






28. 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






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






30. 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






31. 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)






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






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






34. 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






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






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






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






38. Allowance of noise floor below that which is required for the final product






39. 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






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






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






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






43. Decibels Full Scale






44. 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






45. Roughly around 1 -130 ft/s






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






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






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






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






50. As sample rate is increased more room is created for a smoother slope of the attenuation band because Nyquist limit extends well beyond range of hearing with each increase