wavesurfer: 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/wavesurfer - from package: wavesurfer

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

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