Representing Sound
Computer Science: Edexcel IGCSE, topic 3.2.5
Representing Sound
Sounds travels as analogue waves, but computers need to convert this to a digital format.
Sampling
- When sound is recorded by a computer its amplitude is recorded at regular intervals.
- The value of the amplitude at each sample is stored as a binary value.
- The number of bits used to store each sample is known as the sample resolution.
- The number of samples taken per second is known as the sampling frequency.
Quality of audio
- Increasing the sampling frequency will increase the quality of the audio.
- Increasing the sample resolution will also increase the quality of the audio.
- Unfortunately, increasing these make the file size larger.
Bit rate and file size
- The bit rate is the amount of data stored per second of audio.
- The bit rate is calculated as bitrate = sample rate sample size.
Test yourself on Representing Sound
How is audio stored digitally?
Which factors will increase the quality of audio?
What is the drawback of increasing sample resolution and sample frequency?