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






2. Used when the reference pressure of a sound is 20 microPa (0.00002); Sound Pressure Level; Measure of amplitude






3. 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






4. 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)






5. French mathematician that noted that any complex sound can be broken down into a series of component pure tones






6. AES






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






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






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






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






11. The act of a frequency swinging back and forth with a steady - uninterrupted rhythm






12. 8.75 GB; DS/SL






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






14. Computer program or device capable of encoding and/or decoding a digital data stream with the end result being a reduced file size






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






16. 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






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






18. 8- in/8- out on one cable; 25- pin D- sub connector






19. Very quiet digital amplifier that produces a series of output pulses with the audio signal coded the same as the width of the output pulses; Pulses are used to represent wave forms and are either on or off; Intense signals have long pulses with short






20. 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






21. Signal that uses variable voltage to create continuous waves resulting in an inexact transmission






22. Decibels Full Scale






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






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






25. 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






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






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






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






29. When recording you want the smallest buffer available; When mixing you want the largest buffer available






30. 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






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






32. 16-Bit; 44.1 kHz; PCM; Stereo






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






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






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






36. The amount of energy at each wavelength






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






38. Full Scale; Type of metering that measures level in digital recording system; Recording and Mixing levels should NEVER exceed 0dB FS in digital audio or clipping will occur






39. 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.






40. 15.9 GB; DS/DL






41. 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






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






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






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






45. Signal conversions are mixed with playback tracks resulting in near-zero latency






46. Channels are processed one at a time and the results are stored on multiple CPU buffers that alternately send data as DAW requests the data for playback; First few seconds are relayed to the buffer prior to processing and playback and it continuously






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






48. 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






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






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