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






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






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






4. 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






5. 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






6. 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






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






8. 1st commercially successful AoE format for the transmission of digital audio - video - and control signals over 64- channel 100Mbps Ethernet networks






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






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






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






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






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






14. 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)






15. 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






16. 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






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






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






19. 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






20. 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






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






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






23. 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






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






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






26. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






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






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






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






30. 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






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






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






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






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






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






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






37. Multi-Bit Words; (Pulse Code Modulation)






38. 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






39. Measuring equipment in A/D conversion that processes voltage and provides a value for that voltage






40. 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






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






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






43. MPEG; Standardizing body of audio coding






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






45. 'Reconstructing' part of digital audio






46. 8.75 GB; DS/SL






47. 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






48. Method of sampling data at a higher resolution (higher sample rate) as a means of reducing harmonic content during D/A conversion; (x2) oversampling gets rid of all odd harmonic content






49. 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






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