Ruling on entering the bathroom with a Mus-haf or tape of Qur’aan

The scholars clearly stated that taking the Mus-haf into
bathrooms (toilets) and other unclean places is haraam, because that is
disrespectful towards the words of Allaah. However, if a person fears that
it may be stolen if he leaves it outside the bathroom, or he is afraid that
he will forget it, then there is no sin on him if he takes it in, because it
is essential to protect it. 

Tapes are not like
Mus-hafs, because tapes do not contain any writing. All that is there is
certain vibrations which produce sound when passed through a certain
machine. Hence tapes may be taken into the bathroom and there is no problem
with that. 

Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him),
Liqaa’aat al-Baab il-Maftooh, 3/439. 

Shaykh Ibn Baaz (may Allaah have mercy on him) said:  

Entering the bathroom
with the Mus-haf is not permissible except in cases of necessity; if one
fears that it may be stolen, then there is no sin in that. End quote.  

Majmoo’ Fataawa Ibn Baaz, 10/30.