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






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






3. 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






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






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






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






7. Multi-Bit Words; (Pulse Code Modulation)






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






9. MPEG; Standardizing body of audio coding






10. 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






11. Measure of the amplitude of a longitudinal wave






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






13. The difference between the analog value and the approximated digital value due to the 'rounding' that occurs while converting the analog signal to digital






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






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






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






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






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






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






20. AES






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






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






23. 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






24. Voltage -> Dither -> Anti-Aliasing (Low Pass Filter) -> Sample & Hold Circuit -> Successive Approximation/Quantizer --) 100111010 (PCM Audio File)






25. Also known as equal loudness curves; Graph that indicates the average ear sensitivity to different frequencies at different SPL levels (as volume increases - these curves flatten out)






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






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






28. Serial Copy Management System; main difference between AES3 & S/PIDF






29. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






30. Removes high frequency images and noise and smoothes the stair case output coming from of the sample and hold circuit; Also called a SMOOTHING FILTER






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






32. 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






33. The frequency range that is allowed through a filter






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






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






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






37. 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






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






39. Perceptual coding technique that uses louder sounds of a similar frequency to decide what information is to be saved during data reduction






40. Used as the main disc from which other discs are made; Composed of ground glass with a very fine photoresistor layer; An imaging laser burns pit and land patterns in preparation for duplication






41. The amount of energy at each wavelength






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






43. Process that begins with a fast FFT analysis of the spectra of two input signals - then the multiplication of like frequencies - and IFFT to finalize the process






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






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






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






47. Measurement at regular intervals of the amplitude of a varying waveform (in order to convert it to digital form); There must be a minimum of 2 samples for each cycle in a waveform






48. ADAT Optcal; 8- in/8- out on two cables; Fiber- optic - TOSLINK connector






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






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