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






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






3. 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)






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






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






6. Based on psychoacoustics - these are the basis of frequency analysis for a perceptual codec;






7. Subtract place values from the decimal number and place ones or zeros in the correct places






8. 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






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






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






11. Allowance of noise floor below that which is required for the final product






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






13. Roughly around 1 -130 ft/s






14. When recording you want the smallest buffer available; When mixing you want the largest buffer available






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






16. Number of bits per second processed when sampling sound; (Sampling Rate x Bit Depth) = Resolution






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






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






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






20. 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






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






22. The loudest point of a Full Scale system






23. 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






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






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






26. 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






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






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. 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






30. 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






31. 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






32. 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






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






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






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






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






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






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






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






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






41. 8.75 GB; DS/SL






42. Represents the amplitude component of the digital sampling process; Technique of incrementing a continuous analog event into a discrete set of binary digits (bits)






43. 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.






44. Sample Rate x Bit Depth x # of Channels






45. 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






46. 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






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






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






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






50. 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