start-pulseaudio-x11: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/start-pulseaudio-x11 - from package: pulseaudio-module-x11

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/start-pulseaudio-x11 - from package: pulseaudio

You may install the required package with command apt-get install {package}

Error in other languages:
start-pulseaudio-x11: bevel nie gevind nie
start-pulseaudio-x11: comandă negăsită
start-pulseaudio-x11: comando não encontrado
start-pulseaudio-x11: commande introuvable
start-pulseaudio-x11: command not found
start-pulseaudio-x11: käsku ei ole
start-pulseaudio-x11: không tìm thấy lệnh
start-pulseaudio-x11: komanda nerasta
start-pulseaudio-x11: Kommando nicht gefunden.
start-pulseaudio-x11: kommandot finns inte
start-pulseaudio-x11: komut yok
start-pulseaudio-x11: nie znaleziono polecenia
start-pulseaudio-x11: níor aimsíodh an t-ordú
start-pulseaudio-x11: no se encontró la orden
start-pulseaudio-x11: no s'ha trobat l'ordre
start-pulseaudio-x11: opdracht niet gevonden
start-pulseaudio-x11: parancs nem található
start-pulseaudio-x11: perintah tidak ditemukan
start-pulseaudio-x11: príkaz nenájdený
start-pulseaudio-x11: příkaz nenalezen
start-pulseaudio-x11: команда не найдена
start-pulseaudio-x11: командата не е открита
start-pulseaudio-x11: 命令找不到
start-pulseaudio-x11: コマンドが見つかりません