Assalaamu alaykum. What is the ruling of using software to chance one's voice to make it sound like music? Is it halal to listen to this given that there are no instruments playing? The human voice is being changed to sound like them; I heard somone say that some scholars say that it is only haram if instruments are linked to it and that otherwise it is not. Is this true?

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger. 

First of all, you should know that the Shariah puts two things that are similar on an equal footing and does not make a difference between them, in the same manner that it does not consider two things that are different equal.

Shaykh Ibn Taymiyyah said, “The balance that Allah has revealed with the Book (the Quran) is a fair balance; it considers something that resembles another thing as the same, and if they are different, it considers them as different. So it equates two similar things [i.e. it applies the same ruling to them] and distinguishes between two different things [i.e. it gives them different rulings].”

Ibn Al-Qayyim said in Badaa'i Al-Fawaa'id:

“The Shariah does not differentiate between two identical things at all, and it never considers two different things as the same thing; it never forbids something because of its harm while legalizing something whose harm is equal to that which it forbade; and it never considers something lawful for a benefit while it forbids something whose benefit is equal to that which it had considered lawful. There is absolutely nothing like this in what the Prophet brought to us…”

Therefore, if this software makes the human voice sound like music and produces the same melodious effect as that of music, then it takes the same ruling as music. So it is not permissible to listen to that changed voice that became like the sound of music, in the same manner that it is not permissible to listen to music.

Shaykh ‘Abdullah ibn Jibreen was asked, “What is the ruling on making sounds with the mouth that are like the sounds of musical instruments?” He said, “In our view, it is forbidden, because it takes the place of musical instruments, which are forbidden instruments that prevent from the remembrance of Allah, and whatever takes its place is also forbidden.”

Allah knows best.