The study aims to evaluate the impact on the preterm infants' short-term physiological, neurodevelopmental states by employing maternal voice intervention in NICU routine care. This study also evaluates the correlation between effective intervention and maternal depression by employing Edinburgh Postnatal Depression Scale .

The study designs a two-arm, double blind randomized control trial (RCT) experiment in terms of a block randomization for allocating participants in experimental and control groups respectively. In the experimental group maternal voice in terms of lullaby, music, and meaningful words plays near the head of premature infant in the incubator by 30 mins each time, and totally three times a day over a 14-days intervention duration. Meanwhile a standard care treats premature infants in the control group. A IntelliVue physiological monitor and a behavior scale collects ECG, respiratory rate, SpO2 concentration, and sleep/awake states of premature infants in both groups. Finally, ANOVA analyzes the statistical significance between the measurer and items.

Inclusion Criteria:

• Preterm infants at 28-36 gestational age
• Within 10 days in NICU after delivery

Exclusion Criteria:

1. Has a known chromosomal or congenital abnormality
2. Major congenital infection
3. Brain lesions diagnosed prenatally, or neonatal asphyxia at birth.
4. Toxic use by the mother during pregnancy
5. Intraventricular hemorrhage of third degree or more occurred in brain ultrasound examination
6. Are using sedative medication
7. Premature infants use endotracheal tube respirator or high-frequency respirator
8. Preterm infants requiring immediate surgical treatment at birth