“إذا تثاءب أحدكم فليرده ما استطاع فإن أحدكم إذا قال: ها ضحك منه الشيطان”
(خ) عن أبي هريرة.
425 – It is narrated from the words of Abu Huraira, may Allah be pleased with him, that the Prophet (peace and blessings of Allaah be upon him) said:
If any of you (wants to) yawn, let him restrain it as much as possible, for when any of you says: “Ha”  , shaitan laughs at him. ” This hadith was narrated by al-Bukhari 3289, 6223, 6226.
Sheikh al-Albani called the hadith authentic. See “Sahih al-jami ‘as-saghir” 425.
 – That is, makes this yawning sound.