On: Frequency-shaped background noise generators

[shmerl]

Sox can be pretty handy. For example it's easy to use it for musical instruments tuning (instead of buying some expensive electrical device).

For example for mandolin layout:

4 (G):

    while true; do play -n synth pluck G3 fade 0 3 vol 0.4; sleep 1; done

3 (D):

    while true; do play -n synth pluck D4 fade 0 3 vol 0.4; sleep 1; done

2 (A):

    while true; do play -n synth pluck A4 fade 0 3 vol 0.4; sleep 1; done

1 (E):

    while true; do play -n synth pluck E5 fade 0 3 vol 0.4; sleep 1; done