volsay: Wrapper around OSX's `say' command, which sets the system volume to the requested level, then restores volume / mute state once speech is complete.

volsay.sh

#!/bin/bash

function usage() {
  echo "usage: $0 <volume (0-100)> <say args...>"
  echo
  echo "Unmutes and sets the system volume to volume%, passing the remaining"
  echo "arguments to the OSX \`say' command, restoring volume / mute setting"
  echo "to previous values after the speech has completed."
  exit 1
}

# Set volume level (echos current volume level before changing)
function volume() {

  osascript -e 'output volume of (get volume settings)'
  osascript -e "set volume output volume $1"

}

# Set system mute status (echos current mute state before changing)
function mute() {

  mstate=$(osascript -e 'output muted of (get volume settings)')
  echo $mstate

  if [[ $mstate != $1 ]]; then
    osascript -e "set volume output muted $1"
  fi

}


if [[ -z $1 || ! $1 =~ ^[0-9]+$ ]]; then
  usage
  exit 1
fi

oldmute=$(mute false)
oldvol=$(volume $1)
shift
say $*
volume $oldvol > /dev/null
mute $oldmute > /dev/null

This file came up in a search.. It's worth noting that you can pass volume arguments directly to say:

say "[[volm 0.$((RANDOM%9+1))]] Hello"

I realize you are going for a bit more here.

fwiw, the man page should include [[volm <%>]] somewhere