## 1 Introduction  
Prior to establishing newborn hearing screening programs, children with permanent hearing loss showed to have significantly lower language, literacy, and social-emotional outcomes than children without hearing loss [1]. The introduction of newborn hearing screening programs resulted in early identification and early start of intervention and improved developmental outcomes in children with hearing loss [1, 2]. Early enrollment to early intervention services leads to better language, literacy, and social-emotional outcomes than later enrollment [1, 3, 4, 5].  
In the Netherlands, the youth health care services have been performing newborn hearing screening since its nationwide implementation in 2006 [6, 7]. Newborn hearing screening was implemented in line with the European Consensus Statement on Neonatal Hearing Screening [8]. Most children are screened in a three-stage screening program. They are referred to a speech and hearing center for an audiological assessment after not passing the screening for the third time. There is a separate screening program for children in neonatal intensive care units (NICU) in the Netherlands, which concerns 2% of all newborns. In the current study, results from the well-baby hearing screening by the youth health care are reported. To calculate the prevalence of uni- and bilateral hearing loss among all newborns in the Netherlands results from the well-baby and NICU populations are combined.  
The aim of newborn hearing screening is to identify children with a permanent hearing loss with a minimum of 40 dB in one or both ears in order to ensure that intervention can start early. The Joint Committee on Infant Hearing has recommended that newborn babies should receive a hearing screening by 1 month of age, a definitive diagnosis of hearing loss by 3 months of age, and enrollment in early intervention by 6 months of age [9]. These recommendations are commonly referred to as the 1-3-6 guidelines. These guidelines are also followed in the Netherlands, except for completion of screening within the first month of life. In the Netherlands, most children are born at home or in a maternity ward from which they are usually discharged within 24 h. Therefore, approximately 75% of all children are screened in the home environment [10]. For the other children, screening takes place at a well-baby clinic, during a special visit for hearing screening when babies are about 3 weeks old. Therefore, the one-month goal that is set in the international guidelines is extended to 6 weeks in the Netherlands. Since its implementation, the Dutch newborn hearing screening program is very stable and of high quality, with high coverage for each stage of screening and diagnostic testing, low referral rates, and timely screening and diagnosis [10; 11; 12; 13; 14; 15]. This enables reliable statements about prevalence rates of hearing loss. Nationwide studies on the prevalence of permanent hearing loss specified by the severity of hearing loss are scarce. The current study aims at reporting the prevalence of permanent uni- and bilateral hearing loss specified by the severity of hearing loss in a well-baby population. The results from screening to the diagnosis of the well-baby hearing screening program in the Netherlands from 2015 to 2019 will be presented.