Every different species of frog makes it’s own special sound and it is only the male frog that can croak. They have a small sac in their throats that vibrates the air as they slowly let it out.
The sounds that frogs make are not what you’d expect. Did you know that there are frogs that chirp? Others can whistle, croak, ribbit, peep, cluck, bark and grunt.
If you would like to know more there are some websites that have frog sounds you can listen to online: