Fatal error: Call to undefined function audio_prepare()

Fatal error: Call to undefined function audio_prepare() in ...\modules\audio\contrib\attach\audio_attach.module on line 153
This error appear when you want to attach an audio file to a subject of forum for example in my case ( and to a node in general).
Any explanations for this error?
By searching in "audio_attach.module" file, we remark that this audio_prepare () function is called but is not defined.
Are they any development on this issue? Anyone has found a solution for this bug?
Thanks a lot.