The objective of this clinical study is to understand the current status of parent-child bond, parenting role perception and well-being of fathers of preterm infants, and to explore the effect of audio-visual interventions on parent-child bonding, parenting role perception and well-being of fathers of preterm infants. The main questions it aims to answer are:

• After intervention, whether the parent-child connection between fathers and preterm infants in the audio-visual group is higher than that in the audio-visual group and the control group
• After the intervention, whether the father's perception of parenting role in the audio-visual group is higher than that of the vocal group and the control group
• After intervention, whether the father's happiness in the audio-visual group is higher than that in the audio-visual group and the control group The investigators will compare the pre- and post-test methods bwtween the experimental groups and the control group. The fathers of enrolled preterm infants will fill in the structured questionnaires at the time before the intervention (Baseline data) and one month later after the intervention.

This study is a randomized controlled trial, which will compare the pre- and post-test methods between the experimental groups (2 groups) and the control group in an attempt to explore the effect of audio-visual intervention on the parent-child bond, parent-role perception and well-being of fathers of preterm infants.

The total number of participants is estimated as 99. All fathers of preterm infants will complete three questionnaires at the time of 1-3 days , one week, and one month of age of their preterm babies). It will take about 10-20 minutes for questionnaire survey each time. Study participants were randomly assigned to the following three groups (33 in each group):

【Group 1】During the first three days, the researchers will provide a storybook to the father of the premature infant, and the researchers assist in recording the father's voice of the storybook in the form of MP4 recording. At the fourth day, one hour after the baby feeding, the father's voice will be played by the player to the baby, for 2 consecutive days, 2 times/day, 10 minutes/time. The baby's heartbeat, breathing and blood oxygen changes will be recorded and monitored with a physiological monitor. The recording files will be kept by the researcher.

【Group 2】 The intervention will be the same with Group 1 except the following intervention: on the 4th-6th day of the baby's birth, sleeping in the incubator, the baby's reaction behavior will be taken with a mobile phone, 1 time/day, 5 minutes/time, for 3 consecutive days, the image feedback is delivered to the father in person.

【Group 3】This group is a control group. The fathers and preterm infants will not receive interventions conducted in group 1 and 2.

Inclusion Criteria:

• father age > 20
• premature infant born at 29-36 weeks

Exclusion Criteria:

• infant failing the hearing examination
• father and mother are not married