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






2. 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






3. 16-Bit; 44.1 kHz; PCM; Stereo






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






5. Leaving space at beginning and ending of song for data crunching during mastering; Last step in mastering process






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






7. 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






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






9. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






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






11. 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






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






13. 1st commercially successful AoE format for the transmission of digital audio - video - and control signals over 64- channel 100Mbps Ethernet networks






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






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






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






17. 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






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






19. Most significant lossless coding technique in current use; Measure of disorder in which long strings of data are represented by short symbols and uses the shortest symbols to represent the most common repetitive audio data maximizing data reduction






20. The loudest point of a Full Scale system






21. Industry Standards: -6 dB Peak = -20 RMS Meter






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






23. AAC (Advanced Audio Coding); MP3; RA; WMA; OGG Vorbis; Dolby Digital/AC-3; DTS; ADPCM






24. Uses entropy coding as the basis; Computer data compression algorithm that packages files such as .ZIP & .RAR






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






26. Mixing data and control characters in a single operation






27. Digital (binary) measurements of how long each pulse is either on or off; Width of increasing voltage or decreasing voltage is assigned a 1 or 0 respectively






28. Joint-Stereo Technique; Since the human brain is unable to localize sounds at high frequencies well sounds above 9 kHz threshold are encoded in mono






29. 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






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






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






32. 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






33. 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.






34. Data is transmitted over fiber optic lines; Uses a TOSLINK connecter instead of an RCA type; Can transmit multi- channel audio; Not susceptible to ground hum and loops; Able to support far higher rates of data transfer over greater distances than coa






35. The amount of energy at each wavelength






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






37. 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






38. Waveform of a pure tone showing simple harmonic motion






39. The frequency range that is allowed through a filter






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






41. 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






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






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






44. Defines the number of sample per second taken from a continuous signal to make a discrete signal; Governs the frequency response of digital audio






45. 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






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






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






48. Roughly around 1 -130 ft/s






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






50. Measure of the amplitude of a longitudinal wave