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






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






3. Have odd numbered harmonics






4. Occurs as data is assembled into meaningful bits or information and as left & right channels are separated






5. Samples are duplicated and the playback sampling rate correspondingly increased; Significantly raises the Nyquist limit to a range well beyond human hearing; Processing 'pushes' the distortion resulting from quantization error into these higher frequ






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






7. 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






8. More aggressive lossy data reduction techniques that require further manipulation of the stereo field; Examples are 'Intensity' & 'M-S'






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






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






11. 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






12. Overtones that contribute to the timbre of a sound and make up a complex waveform's physical characteristics






13. A frequency specified for a filter (digital or electronic) the marks the point at which the frequency content of a signal is altered +/- 3dB






14. 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






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






16. AES






17. The mathematics - algorithms - and the techniques used to manipulate signals after they have been converted to digital form






18. Waveform of a pure tone showing simple harmonic motion






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






20. 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)






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






22. Sum of all harmonics; Sum of sine and cosine waves which have frequencies f - 2f - 3f - 4f...






23. 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






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






25. Branch of psychology concerned with the subjective perception of sound






26. ABR; Codecs that encode data by determining how dense or sparse areas of the audio are while also keeping bit rate within specified limits to avoid rebuffering






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






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






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






30. Toshiba developed digital audio interface utilizes fiber optics as a transmission medium.






31. Process of building a complex tone by starting with the fundamental frequency and adding pure tone harmonics






32. 8.75 GB; DS/SL






33. 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






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






35. Eight channel digital surround sound system by Dolby






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






37. 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






38. 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






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






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






41. 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.






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






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






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






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






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






47. Measures the highest levels of a signal being recorded or mixed; Monitors for clipping - which occurs at 0dBFS); Does not always reflect perceived volume of signal






48. 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






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






50. Same as 'aliasing'