Background: Children require higher Signal-to-Noise Ratios (SNRs) than adults to achieve equal performance. These performances can be compared using a Proficiency Factor (P), defined as the quotient of the audibility (Speech Intelligibility Index, SII) that is apparently needed and the reference SII. P can be considered as the product of P- Bottom Up (BmUp) and P-Top Down (TpDn), which may both be developing in children. These Proficiency Factors can be used to predict the acoustic requirements (SII or Speech Transmission Index, STI) for children in for example classrooms.

Aims: The aim of this study was to investigate the development of the SRT in school-aged children for relatively “simple” DIN stimuli (Digit-In-Noise), and more complex sentences with keyword scoring (Sentences-In-Noise, SIN-kw). Furthermore, we examined/analyzed age effects of P-BmUp and P-TpDn for these tests.

Methods: The SRT of the DIN and SIN-kw were measured with an adaptive procedure at 50 and 85 % target points in 48 school-aged children (age 4-12) with normal hearing and typical development. Sixteen adults with normal hearing were included for reference data. The relations between outcome measures and age were explored. For each outcome measure, P was estimated as the SII divided by the reference SII. P-BmUp was based on the SRT at 50% DIN target point. P-TpDn was determined by comparing the total P to the P-BmUp.

Results: Analysis of variance showed a significant effect of age for all outcome measures, with better scores for older ages. DIN_85 performance of the children could be fully predicted by P-BmUp. For SIN-kw_50, an extra age-related P-TpDn was needed. The SIN-kw_85 results could be described using the SIN-kw_50-based P-TpDn and the DIN_50-based P-BmUp.

Discussion and Conclusion: Speech recognition develops with age in school-aged children. For DIN, the results can be described by the development of Bottom - Up Proficieny. SIN-kw can be predicted using an additional Top -Down Proficiency. These Proficiency Factors can be used to adjust acoustic requirements (SII or STI) for children. School-aged children need substantial higher SNR (i.e. SII or STI value) for effective speech reception in noise perception compared to older normal hearing listeners.