diff --git a/sh/compandy b/sh/compandy
new file mode 100755
index 0000000..3ea3f37
--- /dev/null
+++ b/sh/compandy
@@ -0,0 +1,21 @@
+#!/usr/bin/zsh
+# script to make sense of compand's parameters
+compandy() {
+    if [ $# -eq 0 ]; then
+        echo -E "usage: $0 {attack} {release} {threshold} {ratio} [knee] [gain] [delay]"
+        return 1
+    fi
+    local atk="${1}" rel="${2}"
+    local thresh="${3}" ratio="${4}"
+    local knee="${5:-1}" gain="${6:-0}" delay="${7:-0}"
+    let 'atk/=1000.'
+    let 'rel/=1000.'
+    let 'delay/=1000.'
+    local end= start=
+    let 'end=thresh - thresh/(ratio + 0.0)'
+    local start=$thresh
+    printf "compand=%.5f|%.5f:%.5f|%.5f:%.1f/%.1f|0/%.2f:%.2f:%.2f:%.1f" \
+      $atk $atk $rel $rel $thresh $thresh $end $knee $gain $start
+    #echo "compand=$atk|$atk:$rel|$rel:$thresh/$thresh|0/$end:$knee:$gain:$start:$delay"
+}
+compandy "$@"