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






3. Waveform of a pure tone showing simple harmonic motion






4. The elapsed time it takes for a packet of data to arrive at its destination; Lagging or pause of an audio signal as digital processing occurs; Can be managed utilizing several forms of 'audio monitoring'






5. 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.






6. Lossless Format; Can hold up to 25GB on a single- layer disc and 50GB on a dual- layer disc






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






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






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. 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






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






12. 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






13. 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






14. Roughly around 1 -130 ft/s






15. 'Reconstructing' part of digital audio






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






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






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






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






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






21. 1.) Taking a series of evenly- spaced measurements 2.) Signal contains no frequency components higher than half the sample rate






22. Decibels Full Scale






23. 4.38 GB; SS/SL






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






25. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






26. Reduces the percieved distortion due to quantization error; Low level white noise source is introduced to make the profile of the quantization 'noise' more irregular; Useful when reducing the number of bits per word in a signal (i.e. when converting






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






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. 7.95 GB; SS/DL






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






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






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






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






34. 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






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






36. 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






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






38. Snippets of time in which frequency analysis takes place in a perceptual codec






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






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






41. 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






42. 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






43. 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)






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






45. 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






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






47. Occurs as data is assembled into meaningful bits or information and as left & right channels are separated






48. 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






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






50. Digital Word -> Series of Resistors (each with assigned charges) -> Sample- and-Hold Circuit -> Anti-Imaging Filter (Smoothing Filter) -> Reconstructed Sample