The loudness value increases or decreases depending on how loud or quiet the microphone input is. If no microphone is available, the value is consistently -1. Sound is measured as a number from 0 to 100. However, it does not use any specific scale, and can only return up to 100, with any sound louder simply returning 100 as well.

Related Blocks

The following block can be used in conjunction with this value:

Prior to Scratch 2.0, the loud?:: sensing block would return true or false if the loudness value was over 30. The block's value could be displayed as a Stage Monitor.

Example Uses

Some common uses for the loudness value are:

  • Voice analyzers
  • Depending on how loud a noise is, the greater response
when gf clicked
point in direction (pick random (-180.0) to (180.0))
move (loudness) steps
if on edge, bounce
  • Setting a microphone's size to a noise's loudness
when gf clicked
set size to ((100)+(loudness))
  • Loudness graphing
when [timer v] > ((-1)/(0)) // Checks if the timer is greater than -Infinity
erase all
pen up
go to x: (-240) y: (0)
pen down
repeat until <(x position) = (240)>. {
set y to (loudness)
change x by (1)


While the loudness blocks sense microphone input, the video sensing blocks sense webcam input. Together, they can be used to sense real-life action, as shown below:

when green flag clicked
    if < <(video (motion v) on (Stage v)) < [30]> and <(loudness) < [30]>> then
        say [No fun!]
    if < <(video (motion v) on (Stage v)) > [30]> and <(loudness) < [30]>> then
        say [Turn up the volume!]
    if <<(video (motion v) on (Stage v)) < [30]> and <(loudness) > [30]>> then
        say [Start moving!]
    if <<(video (motion v) on (Stage v)) > [30]> and <(loudness) > [30]>> then
        say [Party!]

See Also

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