A comparison of NAL and DSL prescriptive methods for paediatric hearing-aid fitting: Predicted speech intelligibility and loudness

Abstract

OBJECTIVE To examine the impact of prescription on predicted speech intelligibility and loudness for children. DESIGN A between-group comparison of Speech Intelligibility Index (SII) and loudness, based on hearing aids fitted according to NAL-NL1, DSL v4.1, or DSL m[i/o] prescriptions. A within-group comparison of gains prescribed by DSL m[i/o] and NAL-NL2 for children in terms of SII and loudness. STUDY SAMPLE Participants were 200 children , who were randomly assigned to first hearing-aid fitting with either NAL-NL1, DSL v4.1, or DSL m[i/o]. Audiometric data and hearing aid data at 3 years of age were used. RESULTS On average, SII calculated on the basis of hearing-aid gains were higher for DSL than for NAL-NL1 at low input level, equivalent at medium input level, and higher for NAL-NL1 than DSL at high input level. Greater loudness was associated with DSL than with NAL-NL1, across a range of input levels. Comparing NAL-NL2 and DSL m[i/o] target gains revealed higher SII for the latter at low input level. SII was higher for NAL-NL2 than for DSL m[i/o] at medium- and high-input levels despite greater loudness for gains prescribed by DSL m[i/o] than by NAL-NL2. CONCLUSION The choice of prescription has minimal effects on speech intelligibility predictions but marked effects on loudness predictions.

Comparing NAL-NL1 and DSL v5 in Hearing Aids Fit to Children with Severe or Profound Hearing Loss: Goodness of Fit-to-Targets, Impacts on Predicted Loudness and Speech Intelligibility

“…The loudness calculations are consistent with increased children's reports about loudness discomfort when they used the DSL v5 prescription than when they used NAL-NL1 in real-world environments. Excessive loudness may lead to potential temporary threshold shifts, which reduce the speech reception ability of the individual child (Ching et al, 2013b).…”

Factors influencing speech perception in noise for 5-year-old children using hearing aids or cochlear implants

“…Most previous studies have excluded children with additional disabilities or those from homes with lower socio-economic status; thereby limiting the applicability of findings to the population of children with hearing loss. However, it is clear that many children with PCHL have other conditions, including additional disabilities (about 20–40%, Ching et al, 2013b, Gallaudet Research institute, 2011), auditory neuropathy spectrum disorder (ANSD; about 10% of children with hearing loss, Ching et al, 2013b) and that demographic characteristics are known to influence learning and development. For this reason, it is important to study population-based cohorts with sufficient power to account for the effects of potential confounders in examining the effect of timing of intervention on speech perception development.…”

Bimodal Stimulation with Cochlear Implant and Hearing Aid in Cases of Highly Asymmetrical Hearing Loss

“…The same surgeon performed implantation all patients. All CIs had been activated 1 month post-implantation, and the map and HA programming had been optimized following the National Acoustics Lab, Non Linear, version 1 protocol (National Acoustics Lab; Macquaire Park, Australia) [13,14] . Ethical clearance was taken for the study from the institutional ethical committee …”