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






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






3. Signal voltage is relayed to a register from sample- and - hold circuit; Holds reference frequencies in binary form that decrease in value; Finds approximated value & assigns binary number accordingly






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






5. Built into DAWs; Bits are added when signals are mixed together to avoid clipping






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






7. Roughly around 1 -130 ft/s






8. Cable used to transmit data; Inner cable is surrounded by a plastic insulator - which is surrounded by a wire mesh conductor that insulates the internal signal wire from external interference and an outer casing that functions as a ground






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






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






12. 7.95 GB; SS/DL






13. 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.






14. Same as 'aliasing'






15. Smallest interval measurable by a scientific instrument; Defined by bit rate (sample rate x bit depth)






16. Have odd numbered harmonics






17. Number of bits used to represent the smallest unit of information in an audio file; Greater bit depth = better quality audio






18. 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






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






20. 1st commercially successful AoE format for the transmission of digital audio - video - and control signals over 64- channel 100Mbps Ethernet networks






21. 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






22. Unit of measurement that is equal to one millionth of a meter






23. 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






24. 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






25. A digital filter's time domain output sequence when the input is a single sample is input






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






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






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. 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






30. (AES/EBU); 110O - 2- channel balanced digital audio cable with an XLR connection; NOT a mic cable!!






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






32. Specific set of instructions for carrying out a data reduction technique that determines how to 'save' binary data information efficiently






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






34. The set of rules that computers use to move files from one computer to another on an internet






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






36. High Pressure - Part of a longitudinal wave where the particles of the medium are close together






37. 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






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






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






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






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






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






43. The amount of energy at each wavelength






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






45. Eight channel digital surround sound system by Dolby






46. 8- in/8- out on one cable; 25- pin D- sub connector






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






48. 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






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






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