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. 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






2. 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






3. A situation where a calculated value cannot fit into the number of digits reserved for it






4. 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






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






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






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






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






9. Reference voltage determined by summing the voltage values of a predetermined number of previous samples; Numbers of 1 in row = waveform peak; Numbers of 0 in row = waveform trough; Basis of Sony's Direct Stream Digital (DSD)






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






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






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






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






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






15. 8.75 GB; DS/SL






16. HD Audio format; Lossless Compression; 24- bit/96 kHz; 5.1 Surround or 24- bit / 192 kHz stereo sound






17. 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






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






19. Found that aliasing was always a problem no matter how fast you sample; Less data recorded but more accurate; 2 samples per wave length.






20. Eight channel digital surround sound system by Dolby






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






22. 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






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






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






25. 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)






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






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






28. 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






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






30. Allows for an internal sample rate at multiples of the input and output rates; Alleviates the need for steep 'brickwall' filters; Often combined with internal '1- bit' processing; Increases smoothing effect






31. 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






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






33. 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






34. 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






35. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






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






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






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






39. 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






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






41. The mathematics - algorithms - and the techniques used to manipulate signals after they have been converted to digital form






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






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






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






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






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






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






48. The frequency range that is allowed through a filter






49. 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






50. As sample rate is increased more room is created for a smoother slope of the attenuation band because Nyquist limit extends well beyond range of hearing with each increase