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






2. ABR; Codecs that encode data by determining how dense or sparse areas of the audio are while also keeping bit rate within specified limits to avoid rebuffering






3. Waveform of a pure tone showing simple harmonic motion






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






5. Serial Copy Management System; main difference between AES3 & S/PIDF






6. Data reduction technique that does not effect quality of original audio; No effect on original quality; Typically around 50% reduction; Exact reconstruction of digital code for the audio signal






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






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






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






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






11. 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






12. 16-Bit; 44.1 kHz; PCM; Stereo






13. EBU






14. 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






15. Removes high frequency images and noise and smoothes the stair case output coming from of the sample and hold circuit; Also called a SMOOTHING FILTER






16. 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.






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






18. Voltage -> Dither -> Anti-Aliasing (Low Pass Filter) -> Sample & Hold Circuit -> Successive Approximation/Quantizer --) 100111010 (PCM Audio File)






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






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






21. 1st commercially successful AoE format for the transmission of digital audio - video - and control signals over 64- channel 100Mbps Ethernet networks






22. Eliminates frequencies above the Nyquist limit from becoming samples; Occurs prior to quantization






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






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






25. RAM holds in memory audio data before it is transferred to the memory controller; Certain amount of data is processed before large amounts of data are streamed to prevent latency






26. 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






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






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






29. 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






30. 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






31. 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






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






33. Measure of sound pressure over the frequency spectrum - for which a listener perceives a constant loudness when presented with pure steady tones






34. The amount of energy at each wavelength






35. 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






36. 'Reconstructing' part of digital audio






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






38. 7.95 GB; SS/DL






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






40. 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






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






42. Sony and Philips optical disc format; Utilizes sigma delta DSD to offer higher resolution; 1- bit; 2.8224 MHz; 6-Channel






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






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






45. 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






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






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






48. The set of rules that computers use to move files from one computer to another on an internet






49. Pertaining to hearing or sound; Combination of the intensity of air pressure molecules with amplitude






50. The frequency range that is allowed through a filter