show noise level

soundmeter.jl

using Statistics

const p = run(pipeline(`arecord -f cd -t raw`, stdout=Pipe()), wait=false)
close(p.out.in)

while true
    sleep(0.1)
    x = reinterpret(Int16, readavailable(p.out))
    x = @. 20log(10, abs(max(x, typemin(Int16) + one(Int16))) / typemax(Int16))
    println(mean(x))
end