Sound!!

Sound!!

1. Key Terms

   • Analogue Sound
     • Original Sound. In analogue recordings, the machine is constantly recording any sound or noise that is coming through the microphones
   • Digital Sound
     • In digital recording you don’t have a constant recording, you have a series of samples or snapshots which are a measure of amplitude at a given point in time and are taken from the sound being recorded.
   • Analogue to Digital Converter
     • An analogue to digital converter constantly measures the amplitude (volume) of an incoming electrical voltage from a microphone or sound source.
   • Quantization
     • Is the name of the audio 'snapshot' when it has to be rounded off to the nearest available digital value.
   • Sampling Rate
     • Sample rates are measured in hertz (Hz) or thousands of hertz (kHz – kilohertz). The samples of audio recorded every second. The sample rate you choose depends on what the audio is going to be used for.
   • Bit Rate
     • Digital music files are measured by the amount of information they can play per second. Usually measured in kbps, or kilobits per second. The amount of sound information presented to the listener every second. The bitrate is the number of bits per second.
   • Bit Depth
     • Bit depth defines the dynamic range of the sound – the amplitude (volume) of the waveform at each sample point.
   • Modulation
     • Modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted.
   • Calculating File Sizes
     • We can calculate sound file sizes based on the sampling rate and the sample resolution using the following formula: File size (bits) = rate × res × secs = sampling rate

2. File Formu