ols_test: 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 Debian possible default full paths are:

/usr/bin/ols_test - from package: speech-tools

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

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