Photo AI
Eight minutes of sound has been digitally recorded - AQA - GCSE Computer Science - Question 5 - 2021 - Paper 1
Question 5
Eight minutes of sound has been digitally recorded. The sampling rate used was 25 000 Hertz and the sample resolution used was 4 bits. 1. Calculate the minimum file... show full transcript
Worked Solution & Example Answer:Eight minutes of sound has been digitally recorded - AQA - GCSE Computer Science - Question 5 - 2021 - Paper 1
Step 1
Calculate the minimum file size for the recording. Give your answer in megabytes.
Answer
To find the minimum file size, we will follow these steps:
-
Convert minutes to seconds:
8 ext{ minutes} = 8 imes 60 = 480 ext{ seconds}
-
Calculate the total number of samples:
Total samples = Sampling Rate × Duration in seconds
= 25,000 ext{ Hz} × 480 ext{ seconds} = 12,000,000 ext{ samples}
-
Calculate the total number of bits:
Total bits = Total samples × Sample Resolution
= 12,000,000 ext{ samples} × 4 ext{ bits/sample} = 48,000,000 ext{ bits}
-
Convert bits to bytes:
Total bytes = Total bits / 8
= 48,000,000 ext{ bits} ÷ 8 = 6,000,000 ext{ bytes}
-
Convert bytes to megabytes:
Total megabytes = Total bytes / 1,000,000
= 6,000,000 ext{ bytes} ÷ 1,000,000 = 6 ext{ MB}
Thus, the minimum file size for the recording is 6 MB.
Step 2
Explain what effects increasing the sampling rate would have on the recording.
Answer
Increasing the sampling rate has several effects on the recording:
-
Higher Audio Quality: A higher sampling rate captures more details of the soundwave, resulting in a more accurate and high-fidelity reproduction of the audio.
-
Increased File Size: As the sampling rate increases, the number of samples taken per second also increases, which leads to larger file sizes for the recordings. This means more storage space is required for the audio files.
-
Potential for More Data Processing: With higher data rates, there may be a greater demand on processing power and data transfer speeds during recording and playback.