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. Measurement at regular intervals of the amplitude of a varying waveform (in order to convert it to digital form); There must be a minimum of 2 samples for each cycle in a waveform






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






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






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






5. Waveform of a pure tone showing simple harmonic motion






6. 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






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






8. Decibels Full Scale






9. 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






10. 8.75 GB; DS/SL






11. 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






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






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






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






15. 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






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






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






18. 12.33 GB; DS/ML






19. 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






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






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






22. Smallest interval measurable by a scientific instrument; Defined by bit rate (sample rate x bit depth)






23. 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);






24. 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






25. Softest sound that can be heard by the average human ear (0 dB)






26. 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






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






28. 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






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






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






31. Amplitude meter that takes the square root of all instantaneous amplitudes and averages them to find a mean and squares that value; Useful with particularly complex waveforms






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






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






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






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






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






37. The amount of energy at each wavelength






38. Only 2 digits used; The value of each place (ones - hundreds - etc.) are as follows from greatest to least: 128 - 64 - 32 - 16 - 8 - 4 - 2 - 1






39. 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






40. Discrete incremental distinctions made between the value of one sample and the next; Breaks down bit depth into a series of evenly spaced intervals






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






42. Rate at which energy is drawn from a source that produces a flow of electricity in a circuit; Expressed in volts






43. 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






44. The process of reducing the space required to store data by efficiently encoding the content.






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






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






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






48. Same as 'aliasing'






49. 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






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