Using a bell in the house, alarm clocks or regular clocks
Question

                There are people who say that alarm clocks are haraam because they have music. Is this correct?.
Praise be to Allah.Muslim narrated in his 
    Saheeh (2113) from Abu Hurayrah (may Allaah be pleased with him) that 
    the Messenger of Allaah  (peace and blessings of Allaah be upon him) 
    said: “The angels do not accompany any group with whom there is a dog or a 
    bell.” 
And he narrated (2114) also 
    from Abu Hurayrah that the Messenger of Allaah  (peace and blessings of 
    Allaah be upon him) said: “Bells are the musical instruments of the 
    Shaytaan.” 
Al-Nawawi (may Allaah have 
    mercy on him) said: As for bells, it was said that the reason why the angels 
    dislike them is that they are similar to church bells, or because they are 
    one of the hanging things that are forbidden. And it was said that the 
    reason why they are disliked is their sound, which is supported by the 
    report which mentions “the musical instruments of the shaytaan.” 
The reason why their sound 
    is disliked is that it is akin to musical instruments, which are forbidden. 
Al-Haafiz Ibn Hajar (may 
    Allaah have mercy on him) said: To sum up, the sound has two qualities, one 
    which is the strength of the sound and the other is its tune, and because of 
    its musical tune it was prohibited, and the reason was given as being 
    because they are “the musical instruments of the shaytaan.”  
Shaykh Ibn ‘Uthaymeen (may 
    Allaah have mercy on him) said: (The Prophet  (peace and blessings of 
    Allaah be upon him)) told us that the angels do not accompany people with 
    whom there is a bell, because when the animals walk, it will make a sound 
    like music, and it is known that musical instruments are haraam. End quote.
    Sharh Riyaadh al-Saaliheen (4/340). 
With regard to alarm clocks 
    and the like, if they have musical sounds then they are haraam, because of 
    the general meaning of the evidence that indicates that musical instruments 
    are haraam. But there is nothing wrong with an ordinary alarm clock. 
Shaykh Ibn ‘Uthaymeen (may 
    Allaah have mercy on him) said: As for alarm clocks and the like that do not 
    come under the prohibition, and things that are used beside doors to ask 
    permission to enter – because some doors have a bell to ask permission to 
    enter – there is also nothing wrong with these, and they do not come under 
    this prohibition, because they are not hung around an animal’s neck and the 
    like, and they do not create a tune which is the reason why the Prophet  
    (peace and blessings of Allaah be upon him) forbade them. End quote. 
Sharh Riyadh 
    al-Saaliheen (4/340-341). 
The Standing Committee was 
    asked: What is the kind of bell that is forbidden? Please note that there 
    are electric bells that make sounds like birds, or bells on alarm clocks 
    where one piece of metal strikes another, and other kinds. 
They replied: 
The bells that are used in 
    houses, schools and so on are permissible, so long as they do not include 
    anything haraam, such as resembling the church bells of the Christians, or 
    have musical sounds. In that case they are haraam for that reason. End 
    quote. 
Fataawa al-Lajnah 
    al-Daa’imah (26/284). 
And Allaah knows best.