Install libportaudio-ocaml-dev by entering the following commands in the terminal:
sudo apt update sudo apt install libportaudio-ocaml-dev
OCaml bindings for the portaudio library
Portaudio is a portable audio I/O library designed for cross-platform support of audio. This package provides OCaml interface to this library. . This package contains all the development stuff you need to develop OCaml programs which use portaudio.