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. Inner ear component that attaches to the stapes and helps to decrease the amplitude of vibrations; Causes the masking phenomenon






2. 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






3. Psychoacoustic model of data reduction used for general audio compression that aims to transmit only features perceptible to the human ear; Useful for mastering streaming media






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






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






6. 7.95 GB; SS/DL






7. 8- in/8- out on one cable; 25- pin D- sub connector






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






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






10. Mixing data and control characters in a single operation






11. Algorithm uses matrix of a mid/side microphone pair to determine a side signal & that signal is reduced then distributed as code in stereo






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






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






14. How Loud (Y-Axis) & How Fast (X-Axis)






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






16. MPEG; Standardizing body of audio coding






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






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






19. 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






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






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






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






23. 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






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






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






26. Very selective method of lowering buffer levels by halting different levels of audio processing






27. Have odd numbered harmonics






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






29. AES






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






31. 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






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






33. 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






34. VBR; Most common & best data reduction technique; Codecs that encode data by determining how dense or sparse areas of the audio are; Can result in buffering issues






35. 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






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






37. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






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






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






40. 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






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






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






43. Same as 'aliasing'






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






45. 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)






46. The frequency range that is allowed through a filter






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






49. 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.






50. 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