aconnect: 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/aconnect - from package: alsa-utils

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

On Debian possible default full paths are:

/usr/bin/aconnect - from package: alsa-utils

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

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