alsactl: 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:

/sbin/alsactl - from package: alsa-utils
/usr/sbin/alsactl - from package: alsa-utils

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

On Debian possible default full paths are:

/usr/sbin/alsactl - from package: alsa-utils

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

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