Datablock: DTMF Tones - [06-06-2021]
Sox pkg
~$ a=(697 770 852 941);b=(1209 1336 1477 1633);c='123A456B789C*0#D';while read -N1 l;do r="${c#*$l}";i=$((${#c}-${#r}-1));[ "$l" = "*" ]&&i=12;play -n synth sin ${a[$((i/4))]} sin ${b[$((i%4))]} remix - trim 0 0.2 2>/dev/null;done