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Abstract This paper reports real world preferences of children in a double-blind, cross-over trial comparing NAL-NL1 and DSL v.4.1 prescriptions. Twenty-four children wore digital WDRC hearing aids at each site (Australia, Canada). Multi-memory hearing aids provided the NAL and DSL programs in each of two memories. Diaries were completed during two counterbalanced trials, providing overall preference, situational preference, and preference comments. Ratings were reliable, and situational preferences factored into quiet/low level situations versus noisy/reverberant/high level situations. Children at both sites used DSL v4.1 for hearing low level speech, or when they wanted to hear loudly and clearly. Children used NAL-NL1 when they wished to hear sounds at a lower level, or to reduce background noise. Children expressed strong preferences for having the choice of both programs. Canadian children were more likely to prefer DSL than were the Australian children. Factors such as listening environment and prior listening experience are discussed in interpreting these findings. Sumario Este trabajo reporta las preferencias de los niños en el mundo real, en un estudio cruzado, doble-ciego que compara las prescripciones NAL-NL1 y DSL v4.1. Veinticuatro niños de dos sitios (Australia, Canada) utilizaron auxiliares auditivos digitales con WDRC. Los auxiliares auditivos con multi-memoria contaban con los programas NAL y DSL en dos de sus memorias. Se completaron diarios durante dos ensayos balanceados que proporcionaban información sobre la prefer-encia general, la preferencia situacional y comentarios sobre la preferencia. Las puntuaciones fueron confiables y la preferencia situacional se clasificaron en situación silente/nivel bajo versus situación ruidosa/reverberante/nivel alto. Los niños de ambos lugares utilizaron DSL v4.1 para escuchar el habla a intensidad baja o cuando querían escuchar alto y claro. Los niños expresaron una fuerte preferencia por poder tener la opción de ambos programas. Los niños canadienses tendieron a preferir DSL más que los niños australianos. Factores como el ambiente sonoro y las experiencias auditivas previas se discuten y se interpretan los hallazgos. [ABSTRACT FROM AUTHOR]

Abstract This paper reports intelligibility judgments and real-life functional performance of 48 children in a double-blind, cross-over trial comparing the NAL-NL1 and the DSL v.4.1 prescriptions. Intelligibility judgments were obtained by using a paired-comparisons procedure with audiovisual stimuli. Functional performance of children during two eight-week periods, each with hearing aids adjusted to one prescription, was assessed by parents and teachers (PEACH and TEACH) and by children's self reports (SELF). Consistently across reports, performance was significantly better in quiet than in noise. On average, better performance in noise (a higher Noise subscale score) was associated with NAL-NL1 than with DSL v.4.1, both for the PEACH and the SELF. This difference was significant for the SELF in Australia. Intelligibility judgments revealed preferences that were equally split between prescriptions in both countries, on average. In the Australian sample, intelligibility judgments agreed with the questionnaire ratings and with parents’ ratings. An increase in preference for NAL was significantly associated with lesser hearing loss. The effect was not significant in the Canadian sample. Sumario Este trabajo reporta juicios de inteligibilidad y rendimiento funcional en la vida real de 48 niños, en un estudio doble ciego cruzado para comparar las prescripciones NAL-NL1 y DSL v.4.1. Los juicios de inteligibilidad se obtuvieron usando comparaciones por pares con estímulos audio-visu-ales. El rendimiento funcional de los niños durante dos perío-dos de ocho semanas, con auxiliares auditivos ajustados a una de las prescripciones, fue evaluado por padres (PEACH) y maestros (TEACH) y por auto-reportes de los niños (SELF). Consistentemente en los reportes, el rendimiento fue signifi-cativamente mejor en silencio que en ruido. En promedio, el mejor rendimiento en ruido (puntuación de una mayor subes-cala de ruido) se asoció con NAL-NL 1 en comparación con DSL v.4.1, ambos con PEACH y SELF. Esta diferencia fue significativa para SELF en Australia. Los juicios de inteligi-bilidad revelaron preferencias que se dividieron igualmente en promedio, entre las prescripciones en ambos países. En la muestra de Australia, los juicios de inteligibilidad estuvieron de acuerdo con las puntuaciones de cuestionarios y con las de los padres. Un aumento en la preferencia por el NAL se aso-ció significativamente con menor pérdida auditiva. El efecto no fue significativo en la muestra de Canadá. [ABSTRACT FROM AUTHOR]

This paper reports speech and loudness measures on a group of children in a double-blind cross-over trial comparing the NAL-NL1 and DSL[i/o] prescriptions. Twenty-four children with hearing impairment were fitted with digital WDRC hearing aids at each site (Australia, Canada). Speech recognition was measured for nonsense syllables and for the 50% correct threshold for sentence recognition in noise. Loudness ratings for sentences were made on a 7-point scale. Measures were made at fitting and repeated following 8-week trials. Fitting orders were randomized and counterbalanced. Significant differences in consonant recognition occurred for individual children. On average, scores at the 80 dB SPL presentation level were better with the NAL-NL1 fitting. Loudness ratings differed at baseline but did not differ following home trials. Speech recognition scores revealed a small but significant interaction of prescription with level in quiet but not in noise. Individual children had significant performance differences. Loudness ratings showed significant acclimatization effects for children at both sites.

This paper examined how hearing aids adjusted for comparing NAL-NL1 with DSLv.4.1 prescription formulas matched prescriptive targets. The real-ear-to-coupler differences (RECD) of 48 children (24 in Australia and 24 in Canada) were measured and used to derive coupler gain targets. Verification of gain and output were carried out in an HA2-2cc coupler. Electroacoustic measurements revealed a minimal difference between NAL-NL1 and DSLv.4.1 frequency-response slopes due to practical limitations of the devices, even though the prescribed differences were large (up to 13 dB/octave). The difference in overall gain was generally achieved in the hearing aids, with DSLv.4.1 prescribing higher overall gain than NAL-NL1. The mean RECD at 4 kHz was 5 dB higher for children in Australia than in Canada. As the same RECDs were used in deriving targets for both prescriptions, this is unlikely to affect the results of the comparison. The impact of a gain difference between prescriptions on children's performance and preferences in real life is reported in separate papers.