A sound clip is recorded for 30 seconds with a sample rate of 8 kHz and a sample resolution of 16 bits.
(a) Calculate the file size in kilobytes. Show your working. [3]
(b) Describe what is meant by sample resolution. [1]
(c) State one effect of increasing the sample rate. [1]
- (a) 8000 × 16 × 30 (= 3 840 000 bits)(1)
- (a) ÷ 8 (= 480 000 bytes) and ÷ 1000(1)
- (a) 480 (kB)(1)
- (b) The number of bits used to store each sample(1)
- (c) Any one: the recording is closer to / a more accurate representation of the original sound; the file size increases(1)
- Answer: (a) 480 kB (b) number of bits per sample (c) better quality / larger file
- Examiner tip: 8 kHz means 8000 samples every second – convert kHz to Hz before multiplying.