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14 - Representing sound basics

 1. MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III) is an audio coding format for __________ audio

  metric

  clockword

  digital

  old fashioned

 2. A "real" sound that we hear every day (like the sound of your friend's voice) is _____________

  (wave like) analogue in nature (tones and rhythms blend smoothly together)

  metallic in nature (in reality sound is made up of tiny metal bits)

  both analogue and digital in nature

  digital in nature (comprised of 1s and 0s)

 3. If a sound has to be handled by a computer any sound source has to be converted to ____________________

  a set of binary numbers

  a set of waves

  None of the above

  a set of CPU signals

 4. What is the difference between analogue and digital recorded sounds?

  An analog sound file is less like the original sound as it is made up of digital bitcoins

  None of the above

  An analog signal is continuous, think: a wave. Digital refers to being stored in bits

  An analog sound file is stored in bits where as a digital file is more advanced and wave like

 5. Digitising' the sound (making it digital) by using an input device connected to your computer is called:

  sampling the sound

  ghosting the sound

  bitling the sound

  digitalising the sound

 6. One device that is involved in capturing analogue sound and converting it into a digital file for use by a PC is a:

  modem

  mouse

  microphone

  internet router

 7. An input device senses incoming sound, it converts the sound into an electrical signal, and then this signal is ……..
datarep_sound_q1.png

  passed on to the ADC (analogue to digital converter) in the sound card

  passed on to the operating system of the PC which will convert the sound into waves

  passed on to the CPU to convert the signal into binary bytes

  passed on to the monitor to interpret the sound and record it directly

 8. A sound card has two jobs. 1. Convert analogue signals to digital for storage and 2…….

  convert digital signals into 24 bit patterns which are read by the speakers

  convert analogue signals into sound waves so the human ear can hear them

  convert digital signals into binary numbers so they can play accurately

  convert stored digital signals into electrical signals to send to the speakers

 9. What are the ADC and DAC?

  They are both sound cards

  Neither of these exist

  They are both binary pattern sequences that are used to encode sound

  Analogue to Digital Converter and the Digital to Analogue Converter

 10. What needs to happen in order to play a sound (via a computer speaker)?

  File opened. Binary numbers fed through DAC. Amplification applied to power the speakers and play sound

  File opened. Binary numbers passed through the speakers directly

  None of the above

  File opened. Binary numbers fed through the ADC. Speakers use a sound card to re-convert to bits

 11. Sound is measured in cycles per second or _______________________

  Watts

   Hertz

  Bits

  Amps

 12. The higher the frequency (in hertz) the….

  the higher pitched it sounds

  the quieter it is

  None of the above

  lower pitched it sounds

 13. Tone is one thing, but loudness of sound also matters! Because sound is a ________, the loudness is the ________ of the wave

  freight

  depth

  height (amplitude)

  width

 14. ______________ is a method of converting an analogue sound signal into a set of binary numbers that are stored in digital format.

  sampling

  frequenting

  bimping

  amplituding

 15. What is the sampling frequency or rate?

  the rate at which binary sequences are converted into waves

  None of the above

  the rate at which sound is stored as waves and the length changes

  This is the rate at which samples are taken (stated in Kilohertz (thousand times per second)

 16. There is a _________________ at which samples need to be taken in order to faithfully reproduce the original signal

  minimum bit rate (expected number of bits)

  dim rate

  minimum sampling rate (at least twice the highest frequency in the signal)

  maximum sampling rate

 17. For a CD that has sound going up to about 20KHz, the minimum sampling rate is…
datarep_sound_q2.png

  20KHz

  140 KHz

  40KHz

  70KHz

 18. Getting the sampling rate right is important for capturing…..

  sampling keys

  multiple waves

  frequency information

  binary bits

 19. Another thing that is important to consider in this unit is the ______________

  light vs sound dilemma

  binary vs wave duality

  accuracy of the measurement

  accuracy of the number of bits

 20. The number of bits which are used per sample is called the:

  binary bit wave

  Accuracy of binary numbers

  wave amplitude

  Sampling bit depth

 21. Higher bit depth audio will sound …………………..
datarep_sound_q3.png

  worse than a lower one

  None of the above

  the same as a lower one

  better than a lower one

 22. As bit depth and sample rate increase…..
datarep_sound_q4.png

  more information is captured, which causes blockage, and reduces audio quality

  the same amount of information is captured, which is why sound always sounds the same

  more information is captured resulting in higher quality audio

  less information is captured resulting in lower quality audio

 23. Sampling resolution: In the diagram above, a sample can only have _____________ as represented by the 2 bit number
datarep_sound_q5.png

  three values

  two values

  eight values

  four values

 24. In the image below The 11KHz sound sample is far lower quality than the 44 KHz sample, but on the other hand …….
datarep_sound_q6.png

  the number of bits per wave is reduced

  the Khz is increased exponentially

  the file size is 30 times bigger

  the file size is 30 times smaller.

 25. Whenever a sound is sampled, you should ensure that the recording system________________otherwise the re-played sound will have some serious distortion.

   can handle the largest signal and the smallest signal,

  can obliterate itself

  can convert itself into bits

  can handle only the smallest signal

 26. The bit rate is the amount of information required to describe one second of sound. The formula is:

  Bit rate = sample rate x bit depth x number of channels

  Bit rate = bit depth x channel rate

  Bit rate = bit depth + number of channels + sample rate

  Bit rate = sample rate x bit rate x sample rate x 2

 27. Which of the following is the correct formula for bit rate?
a) Frequency × bit depth × channels = bit rate

b) Frequency × channels x bytes = bit rate

c) Frequency × bit rate x frequency x 2 = bit rate

d) Sampling size × bit depth × channels = bit rate

  b

  a

  c

  d

 28. The unit for bit rate is:

  bits per second

  bits per mile

  Hertz

  samples per second

 29. A CD quality stereo audio recording with two channels would require: Bit rate = 44,100 x 16 ______________

  x 20 = 2000,00021231 bits per mile

  x 3 = 150,22,2343 samples per second

  x 2 = 1,411,200 bits per second (1.4 Mbps)

  x 6 = 1882919281 bits per second

 30. The disadvantage of having a very high bit rate is ….

  producing very small file sizes

  producing very loud audio files

  producing very large file sizes

  producing very quiet audio files

 31. You can reduce the bit rate without sacrificing too much quality by using a technique called:

  sacrificialsounding

  sampling

  compression

  meshing

 32. To work out the total size of an audio file, you….

  take the bit rate and multiply it by the sampling rate + bit depth

  take the bit rate and multiply it by the length of the file in seconds

  take the bit rate and multiply it by itself

  take the bit rate and multiply it by the number of bits contained in the file itself

 33. Complete the formula:

  sample rate + bit rate + sample depth

  length * sample rate

  bit rate * 256

  bit rate * length

 34. Given the followig details, what is the storage requirement?

  127 million bits

  200.21 mebgabits

  3423 Hertz

  2000 bits

 35. As there are 8 bits to a byte, the storage for an uncompressed 3 minute CD quality recording is:

  bytes of storage = 100 / 2 = 50 Megabytes

  bytes of storage = 32 / 2 = 16 Megabytes

  bytes of storage = 127 Megabits / 8 = 31 Megabytes

  None of the above

 36. (Most) humans use two ears to hear. A channel is a single sound stream.

  FALSE

  TRUE

 37. Mono sound has information about only a single source or single channel

  TRUE

  FALSE

 38. Stereo sound also called ________ sound will have ______ channels, to make use of multiple speakers. Each channel needs its own samples

  stereo / multiple

  multiple / sony

  multiple / mentored

  configured / strero

 39. In order for an audio player to play back a sound file, the file needs meta data (extra information) on top of the samples.

  1,3,5,7

  all of the above

  1,2,3,4,5

  none of the above

 40. The longer the sampling lasts the smaller the file will be

  FALSE

  TRUE

 41. A bit depth of 8 bits allows 256 levels of the wave to be measured

  TRUE

  FALSE

 42. Doubling the bit depth will ______________________________

  double the file size

  None of the above

  triple the file size

  half the file size

 43. The higher the bit depth, the worse the percieved quality of sound.

  TRUE

  FALSE

 44. Bit rate (bits per second) is a product of sample rate, channel compression rate and four times the sample bit depth

  TRUE

  FALSE

 45. An uncompressed file format is WAV and a compressed format is a MP3

  TRUE

  FALSE

 46. MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III) is an audio coding format for __________ audio

  digital

  clockword

  old fashioned

  metric

 47. A "real" sound that we hear every day (like the sound of your friend's voice) is _____________

  (wave like) analogue in nature (tones and rhythms blend smoothly together)

  metallic in nature (in reality sound is made up of tiny metal bits)

  both analogue and digital in nature

  digital in nature (comprised of 1s and 0s)

 48. If a sound has to be handled by a computer any sound source has to be converted to ____________________

  a set of binary numbers

  None of the above

  a set of waves

  a set of CPU signals

 49. What is the difference between analogue and digital recorded sounds?

  None of the above

  An analog sound file is stored in bits where as a digital file is more advanced and wave like

  An analog sound file is less like the original sound as it is made up of digital bitcoins

  An analog signal is continuous, think: a wave. Digital refers to being stored in bits

 50. Digitising' the sound (making it digital) by using an input device connected to your computer is called:

  bitling the sound

  sampling the sound

  ghosting the sound

  digitalising the sound

 51. One device that is involved in capturing analogue sound and converting it into a digital file for use by a PC is a:

  internet router

  mouse

  microphone

  modem

 52. An input device senses incoming sound, it converts the sound into an electrical signal, and then this signal is ……..
datarep_sound_q1.png

  passed on to the ADC (analogue to digital converter) in the sound card

  passed on to the CPU to convert the signal into binary bytes

  passed on to the operating system of the PC which will convert the sound into waves

  passed on to the monitor to interpret the sound and record it directly

 53. A sound card has two jobs. 1. Convert analogue signals to digital for storage and 2…….

  convert digital signals into 24 bit patterns which are read by the speakers

  convert analogue signals into sound waves so the human ear can hear them

  convert digital signals into binary numbers so they can play accurately

  convert stored digital signals into electrical signals to send to the speakers

 54. What are the ADC and DAC?

  They are both sound cards

  They are both binary pattern sequences that are used to encode sound

  Neither of these exist

  Analogue to Digital Converter and the Digital to Analogue Converter

 55. What needs to happen in order to play a sound (via a computer speaker)?

  File opened. Binary numbers fed through DAC. Amplification applied to power the speakers and play sound

  File opened. Binary numbers fed through the ADC. Speakers use a sound card to re-convert to bits

  None of the above

  File opened. Binary numbers passed through the speakers directly

 56. Sound is measured in cycles per second or _______________________

  Amps

  Watts

  Bits

   Hertz

 57. The higher the frequency (in hertz) the….

  the quieter it is

  lower pitched it sounds

  None of the above

  the higher pitched it sounds

 58. Tone is one thing, but loudness of sound also matters! Because sound is a ________, the loudness is the ________ of the wave

  height (amplitude)

  width

  depth

  freight

 59. ______________ is a method of converting an analogue sound signal into a set of binary numbers that are stored in digital format.

  sampling

  amplituding

  frequenting

  bimping

 60. What is the sampling frequency or rate?

  This is the rate at which samples are taken (stated in Kilohertz (thousand times per second)

  None of the above

  the rate at which sound is stored as waves and the length changes

  the rate at which binary sequences are converted into waves

 61. There is a _________________ at which samples need to be taken in order to faithfully reproduce the original signal

  minimum bit rate (expected number of bits)

  maximum sampling rate

  minimum sampling rate (at least twice the highest frequency in the signal)

  dim rate

 62. For a CD that has sound going up to about 20KHz, the minimum sampling rate is…
datarep_sound_q2.png

  140 KHz

  20KHz

  40KHz

  70KHz

 63. Getting the sampling rate right is important for capturing…..

  multiple waves

  binary bits

  frequency information

  sampling keys

 64. Another thing that is important to consider in this unit is the ______________

  accuracy of the number of bits

  accuracy of the measurement

  binary vs wave duality

  light vs sound dilemma

 65. The number of bits which are used per sample is called the:

  wave amplitude

  Accuracy of binary numbers

  Sampling bit depth

  binary bit wave

 66. Higher bit depth audio will sound …………………..
datarep_sound_q3.png

  None of the above

  the same as a lower one

  worse than a lower one

  better than a lower one

 67. As bit depth and sample rate increase…..
datarep_sound_q4.png

  less information is captured resulting in lower quality audio

  more information is captured, which causes blockage, and reduces audio quality

  more information is captured resulting in higher quality audio

  the same amount of information is captured, which is why sound always sounds the same

 68. Sampling resolution: In the diagram above, a sample can only have _____________ as represented by the 2 bit number
datarep_sound_q5.png

  four values

  two values

  three values

  eight values

 69. In the image below The 11KHz sound sample is far lower quality than the 44 KHz sample, but on the other hand …….
datarep_sound_q6.png

  the Khz is increased exponentially

  the file size is 30 times smaller.

  the file size is 30 times bigger

  the number of bits per wave is reduced

 70. Whenever a sound is sampled, you should ensure that the recording system________________otherwise the re-played sound will have some serious distortion.

   can handle the largest signal and the smallest signal,

  can obliterate itself

  can handle only the smallest signal

  can convert itself into bits

 71. The bit rate is the amount of information required to describe one second of sound. The formula is:

  Bit rate = sample rate x bit rate x sample rate x 2

  Bit rate = sample rate x bit depth x number of channels

  Bit rate = bit depth + number of channels + sample rate

  Bit rate = bit depth x channel rate

 72. To work out the bit rate for one second of audio you would have to:

  FALSE

  TRUE

 73. The unit for bit rate is:

  samples per second

  Hertz

  bits per mile

  bits per second

 74. A CD quality stereo audio recording with two channels would require: Bit rate = 44,100 x 16 ______________

  x 6 = 1882919281 bits per second

  x 20 = 2000,00021231 bits per mile

  x 3 = 150,22,2343 samples per second

  x 2 = 1,411,200 bits per second (1.4 Mbps)

 75. The disadvantage of having a very high bit rate is ….

  producing very quiet audio files

  producing very large file sizes

  producing very small file sizes

  producing very loud audio files

 76. You can reduce the bit rate without sacrificing too much quality by using a technique called:

  sacrificialsounding

  meshing

  sampling

  compression

 77. To work out the total size of an audio file, you….

  take the bit rate and multiply it by the number of bits contained in the file itself

  take the bit rate and multiply it by the length of the file in seconds

  take the bit rate and multiply it by the sampling rate + bit depth

  take the bit rate and multiply it by itself

 78. Complete the formula:

  length * sample rate

  bit rate * 256

  sample rate + bit rate + sample depth

  bit rate * length

 79. Given the followig details, what is the storage requirement?

  2000 bits

  200.21 mebgabits

  127 million bits

  3423 Hertz

 80. As there are 8 bits to a byte, the storage for an uncompressed 3 minute CD quality recording is:

  bytes of storage = 100 / 2 = 50 Megabytes

  bytes of storage = 32 / 2 = 16 Megabytes

  None of the above

  bytes of storage = 127 Megabits / 8 = 31 Megabytes

 81. (Most) humans use two ears to hear. A channel is a single sound stream.

  TRUE

  FALSE

 82. Mono sound has information about only a single source or single channel

  FALSE

  TRUE

 83. Stereo sound also called ________ sound will have ______ channels, to make use of multiple speakers. Each channel needs its own samples

  multiple / mentored

  configured / strero

  multiple / sony

  stereo / multiple

 84. In order for an audio player to play back a sound file, the file needs meta data (extra information) on top of the samples.

  1,3,5,7

  none of the above

  1,2,3,4,5

  all of the above

 85. The longer the sampling lasts the smaller the file will be

  FALSE

  TRUE

 86. A bit depth of 8 bits allows 256 levels of the wave to be measured

  TRUE

  FALSE

 87. Doubling the bit depth will ______________________________

  None of the above

  double the file size

  half the file size

  triple the file size

 88. The higher the bit depth, the worse the percieved quality of sound.

  TRUE

  FALSE

 89. Bit rate (bits per second) is a product of sample rate, channel compression rate and four times the sample bit depth

  FALSE

  TRUE

 90. An uncompressed file format is WAV and a compressed format is a MP3

  TRUE

  FALSE