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






2. Circuit that interprets the meaning of the symbols as they were chosen and arranged by the encode






3. Number or variable that represents the number of times the base of a power is used as a factor; Defines magnitude






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






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






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






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






8. Reduces A/D sample rate from the oversampled rate to nominal rate by turning series of one- bit samples into a series of multi- bit PCM samples; (ex. => 2.8MHz sample rate converted to 44.1kHz and simultaneously converts 1-Bit samples to multi- bit);






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






10. 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






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






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






13. Digital and analog processing capability is combined on a single microchip allowing for 1- bit resolution at high sample rates






14. 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






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






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






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






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






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






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






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






22. 16-Bit; 44.1 kHz; PCM; Stereo






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






24. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






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






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






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






28. 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






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






30. If a signal is sampled at a rate higher than twice the highest significant signal frequency and at evenly spaced intervals - then the samples contain all the information of the original signal






31. 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






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






33. 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)






34. 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.






35. In order to play multiple channels at one time data is buffered as read to disk; Latency happens between play command & beginning of playback






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






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






38. MPEG; Standardizing body of audio coding






39. 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






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






41. Measure of the amplitude of a longitudinal wave






42. Sample Rate x Bit Depth x # of Channels






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






44. Waveform of a pure tone showing simple harmonic motion






45. 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






46. The loudest point of a Full Scale system






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






48. Circuit that seizes voltage values with each tick of an A/D device's internal clock






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






50. Same as 'aliasing'