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. 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






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






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






4. Roughly around 1 -130 ft/s






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






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






7. 12.33 GB; DS/ML






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






9. Describes various optical disc characteristics including the size and shape of the disc - the size of pits - the speed at which the disc spins - and a multitude of aspects regarding the specifications of the player itself






10. 4.38 GB; SS/SL






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






12. 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






13. Waveform of a pure tone showing simple harmonic motion






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






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






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






17. Splits the input signal and mixes it with an analog copy so that no latency is present






18. 1st commercially successful AoE format for the transmission of digital audio - video - and control signals over 64- channel 100Mbps Ethernet networks






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






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






21. Difference in brightness between land and pit on a CD Physical Format






22. Method of representing an acoustic quantity with a series of binary numbers; Can have only specific individually distinct values






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






24. Mixing data and control characters in a single operation






25. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






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






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






28. 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






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






30. 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






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






32. 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






33. 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






34. 16-Bit; 44.1 kHz; PCM; Stereo






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






36. Twice as many samples as the highest frequency at minimum; Sampling rate totally controls frequency response






37. Data reduction technique that selectively removes original information in order to significantly reduce the file size; Some data is lost; Files can be reduced up to 99% in size (90% with no perceived sound quality loss); Bit rate effects the perceive






38. 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.






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






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






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






42. Based on Full Scale (dB/FS); -6dB represents a loss of one bit so account for this when calculating






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






44. 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






45. 'Capturing' part of digital audio; Never captures a signal perfectly






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






47. A network communications protocol that specifies how machines will exchange data; Uses a broadcast system in which one machine transmits its message on the communication medium and the other machines listen for messages directed to them






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






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






50. 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