Crying is a survival mechanism for babies and their almost exclusive means of expression until the age of 4 months. Babies 'cry is mostly related to pain, a feeling of hunger, discomfort or separation following the departure of a parent around. Crying is a complex but essential means of communication and information between a baby and his parents that raises the question of their meaning.

Very few longitudinal studies have been produced on preterm's crying. As the term approaches, the characteristics of preterm babies' crying are similar to those of term infants. But these studies date back more than 30 years and are obsolete in terms of the quality and performance of sound recording equipment and signal processing.

No study has looked at the genesis of the cry itself and the varieties of the cry of the preterm baby, depending on whether it was in a situation of hunger, pain, discomfort (bath).

This longitudinal study recordings of crying babies from 26 amenorrhea week to 33 amenorrhea week, 24 hours per week, each week until the return home. In the same time, parents will be asked to know the situation of the baby (hunger, pain, bath).

Inclusion Criteria:

• Infant born between 26 and 33 amenorrhea week
• Live infant at birth
• Parent affiliated or entitled to a social security scheme
• Parent who received informed written information about the study

Exclusion Criteria:

- Intubated infant

Infant born between 26 and 33 amenorrhea week will be included.