It is quite essential for preemies to have a clean, quiet environment. Soft music and parents talking softly to them, as well as touching and holding them, is quite essential for them to not only get used to your voice and touch, but they need these things for them to grow.
I have a friend Denise. Her daughter was a preemie. The first night home Michelle cried . Denise called the hospital fearing something may be wrong. She was instructed that Michelle got used to the sounds of the NICU and to try mimicing those sounds. The sounds of a ticking clock for example .It worked.
It also is essential that they stay warm. Babies who are cold do not grow as well. Preemies do not have the ability to shiver (I was told by a NICU nurse). Instead, the stress of being cold causes them to have internal reactions affecting their red blood cells. So keep your baby covered and do not set their crib under an air condition vent or near a window. As you read whatever you can find regarding growth and development of preemies, you will learn many things about how to help them thrive. Congratulations on the birth of your baby!