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






2. The amount of energy at each wavelength






3. 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






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






5. Pertaining to hearing or sound; Combination of the intensity of air pressure molecules with amplitude






6. Channels are processed one at a time and the results are stored on multiple CPU buffers that alternately send data as DAW requests the data for playback; First few seconds are relayed to the buffer prior to processing and playback and it continuously






7. 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






8. 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






9. MPEG; Standardizing body of audio coding






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






11. 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






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






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






14. 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






15. 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






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






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






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






19. Measure of the amplitude of a longitudinal wave






20. 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






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






22. EDL; Final list of samples used in the audio editing process; Identified by time code






23. 15.9 GB; DS/DL






24. 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






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






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






27. DAW's and software must buffer when converting or bouncing and this latency can add up if not monitored






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






29. 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.






30. Eight channel digital surround sound system by Dolby






31. The frequency above or below which attenuation begins in a filter circuit






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






33. 12.33 GB; DS/ML






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






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






36. 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






37. 'Reconstructing' part of digital audio






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






39. Reduces A/D sample rate from the oversampled rate to nominal rate by turning series of one- bit samples into a series of multi- bit PCM samples; (ex. => 2.8MHz sample rate converted to 44.1kHz and simultaneously converts 1-Bit samples to multi- bit);






40. Visual graph that shows how loud a sound is at different frequencies






41. Father of modern information theory; Solidified the Nyquist Theory by adding the concept that bits per second (binary representation of audio signals) must be at equal intervals to accurately represent data






42. Playback; I/O Connections; CPU (Streaming); Conversion from DAW or Software






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






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






45. RAM holds in memory audio data before it is transferred to the memory controller; Certain amount of data is processed before large amounts of data are streamed to prevent latency






46. 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






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






48. The act of a frequency swinging back and forth with a steady - uninterrupted rhythm






49. EBU






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