puter-science/aqa/questions","basePath":"/gcse/computer-science/aqa/representing-sound/questions","formulaUrl":null,"initialIndex":5,"initialQuestionWindow":[{"id":"0c929a54-fb8c-41fe-9a48-18276c01c0fa","revisionId":"ed9ee478-d2ef-48d2-84ca-4d0ca02aab46","questionNumber":null,"questionType":"LA","specification":"An acoustic monitoring station is deployed in a nature reserve to record the ultrasonic echolocation calls of bats. The digital recorder captures audio at a sampling rate of 192,000 Hz and a sample resolution of 24 bits.","difficulty":4,"difficultyBand":"medium","totalMarks":4,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"44cc693a-18a3-457c-b649-05e5b6970ee5","label":null,"content":"Calculate the minimum file size, in bytes, of a continuous recording lasting 2.5 seconds.\n\nYou should show your working.","markscheme":"- Identifies the need to use the formula $\\text{File size} = \\text{Sampling rate} \\times \\text{Sample resolution} \\times \\text{Duration}$ or writes down the product: $192,000 \\times 24 \\times 2.5$ M1\n- Calculates the total size in bits as $11,520,000$ bits OR converts the 24-bit resolution to $3$ bytes ($24 \\div 8$) A1\n- Shows division of the total bits by 8 to convert to bytes: $\\frac{11,520,000}{8}$ OR calculates file size directly as $192,000 \\times 3 \\times 2.5$ M1\n- Obtains the correct final answer of $1,440,000$ (or $1,440,000\\text{ bytes}$) A1","marks":4,"order":0,"markingRubric":null,"explanation":null,"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"10a9b4e6-f4c7-4c32-99aa-5c663c2c5057","revisionId":"3e9eb450-9f72-4d31-b712-26dafd1c3911","questionNumber":null,"questionType":"LA","specification":"A software developer is recording a voice clip for a mobile application. The audio is recorded with a sampling rate of 3,000 Hz and a sample resolution of 16 bits.","difficulty":3,"difficultyBand":"medium","totalMarks":4,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"55395213-9720-4e7d-ba71-72a4c2695e5e","label":null,"content":"Calculate the minimum file size of an 8-second audio recording. Give your answer in **bytes**.\n\nYou should show your working.","markscheme":"- Shows substitution of correct values into the formula: $3,000 \\times 16 \\times 8$ M1\n- Obtains a correct intermediate calculation of $384,000$ bits OR converts $16$ bits to $2$ bytes M1\n- Divides by $8$ to convert bits to bytes (or demonstrates correct calculation using $2$ bytes) M1\n- Obtains the final answer of $48,000$ bytes A1","marks":4,"order":0,"markingRubric":null,"explanation":null,"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"14c7131f-247d-468f-8356-fd04452e517e","revisionId":"740d2eb4-42a7-4c5f-80a4-a1be91edf552","questionNumber":null,"questionType":"LA","specification":"","difficulty":3,"difficultyBand":"medium","totalMarks":3,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"cc3332f6-2518-4286-95b1-60f4ce1971a6","label":null,"content":"Explain how an analogue audio signal from a microphone is converted into a digital format so that it can be stored on a computer.","markscheme":"- States that the continuous analogue sound wave is sampled (measured) at regular/periodic time intervals B1\n- Explains that the amplitude (or height/voltage) of the wave at each sample point is measured and assigned a numerical/digital value B1\n- Explains that these discrete numerical values are then saved as a sequence of binary codes/numbers representing the audio B1","marks":3,"order":0,"markingRubric":null,"explanation":null,"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null}],"subjectCode":"gcse_computer_science__aqa","summaries":[{"id":"00e5fca2-2c20-4361-ad53-2845355ff80c","difficultyBand":"medium","calculatorUse":null},{"id":"03757f99-c78e-4c15-95d2-7d246d64b845","difficultyBand":"medium","calculatorUse":null},{"id":"091f2dc7-f3d6-4c

Representing sound

Question 4

Representing sound Questions

Representing sound

Question 4

Representing sound Questions