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






2. Method used in digital recording and reproduction in which a signal is sampled at various points and the resulting value is translated into binary numbers






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






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






5. Computer program or device capable of encoding and/or decoding a digital data stream with the end result being a reduced file size






6. 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






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






8. ADPCM; Pulse code modulation that produces a digital signal with a lower bit rate than standard PCM; Records only the difference between samples






9. 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






10. 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






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






12. 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






13. Increases or decreases the digital signal so that the loudest sample is brought up to 0dBfs; Uses all bits from dynamic range and makes it even from track to track






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






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






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






17. Mixing data and control characters in a single operation






18. Signal that uses variable voltage to create continuous waves resulting in an inexact transmission






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






20. 16-Bit; 44.1 kHz; PCM; Stereo






21. 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






22. 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.






23. 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






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






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






26. 8- in/8- out on one cable; 25- pin D- sub connector






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






28. 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)






29. Measure of sound pressure over the frequency spectrum - for which a listener perceives a constant loudness when presented with pure steady tones






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






31. 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






32. 15.9 GB; DS/DL






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






34. 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






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






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






37. 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






38. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






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






40. 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






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






42. Decibels Full Scale






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






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






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






46. AES






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






48. 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






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






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