Characteristics of all participants.

aSocioeconomic status score was measured by parental education, job, and net income. (Unfortunately, due to privacy reasons, almost half of the parents did not fill out the question concerning the net income, so these were not taken into account.) bSpoken language skills were derived from the Clinical Evaluation of Language Fundamentals; see Materials section for more information. cSign language skills were derived from the Assessment Instrument for Sign Language of the Netherlands; see Materials section for more information. dHigher scores indicate more (social) language problems. More than 70% of the parents responded. eDegree of hearing loss was calculated by averaging unaided hearing thresholds at 500, 1,000, and 2,000 Hertz. 1p<.001; 2p<.01; 3p<.05.