Quick mute Thunderbird notification sound (bash script)

thunderbird-sound-control.sh

#!/bin/bash

SND_ON="/Users/me/Music/win95.wav"
SND_OFF="/Users/me/Music/silent.wav"
SND_ALIAS="/Users/me/Music/thunderbird_notify.wav"

HASH_ON=$(md5 -q ${SND_ON})
HASH_OFF=$(md5 -q ${SND_OFF})
HASH_ALIAS=$(md5 -q ${SND_ALIAS})

CL_BLUE="\033[34m"
CL_PINK="\033[35m"
CL_RESET="\033[0m"

if [ "${HASH_ALIAS}" = "${HASH_OFF}" ];then
	cp -p ${SND_ON} ${SND_ALIAS} && \
	echo -e "OFF --> ${CL_BLUE}ON${CL_RESET}"
elif [ "${HASH_ALIAS}" = "${HASH_ON}" ];then
	cp -p ${SND_OFF} ${SND_ALIAS} && \
	echo -e "ON --> ${CL_PINK}OFF${CL_RESET}"
else
	cp -p ${SND_ON} ${SND_ALIAS} && \
	echo -e "??? --> ${CL_BLUE}ON${CL_RESET}"
fi