The Desired Sensation Level Multistage Input/Output Algorithm

Abstract

The Desired Sensation Level (DSL) Method was revised to support hearing instrument fitting for infants, young children, and adults who use modern hearing instrument technologies, including multichannel compression, expansion, and multimemory capability. The aims of this revision are to maintain aspects of the previous versions of the DSL Method that have been supported by research, while extending the method to account for adult-child differences in preference and listening requirements. The goals of this version (5.0) include avoiding loudness discomfort, selecting a frequency response that meets audibility requirements, choosing compression characteristics that appropriately match technology to the user's needs, and accommodating the overall prescription to meet individual needs for use in various listening environments. This review summarizes the status of research on the use of the DSL Method with pediatric and adult populations and presents a series of revisions that have been made during the generation of DSL v5.0. This article concludes with case examples that illustrate key differences between the DSL v4.1 and DSL v5.0 prescriptions. et al., 1995).Since that revision, DSL[i/o] has been evaluated in both adult and pediatric populations in a number of studies. In this chapter, we will summarize the current status of DSL evaluation work in children and adults and argue the need for different prescriptive targets for adults and children. We will also present research describing electroacoustic and signal processing issues that have motivated us to make modifications to the input/output structure of the DSL target functions. These modifications will be described, and several case studies will illustrate the magnitude and type of changes to prescriptive targets in DSL v5.0. Outcomes for ChildrenStudies using the DSL Method with the pediatric population have been done with various aims and purposes. Some studies have sought to determine whether DSL-related outcomes differ from those of alternative fittings (Snik and Stollman, 1995;Ching et al., 1997;Scollie et al. 2000) or to compare subversions of DSL such as linear vs nonlinear (Jenstad et al., 1999;Jenstad et al., 2000). Other studies have used DSL as the fitting method within general pediatric hearing and amplification research, such as when evaluating signal processing options or audibility effects in children with hearing loss (Moeller et al., 1996;Bamford et al., 1999;Christensen, 1999;Gravel et al., 1999;Hanin, 1999;Lear et al., 1999;Pittman and Stelmachowicz, 2000;Stelmachowicz et al., 2000;Stelmachowicz et al., 2001;Condie et al., 2002;Stelmachowicz et al., 2002). Other authors incorporate the DSL Method, including the associated clinical procedures described by Bagatto et al., 2005, within recommended clinical guidelines for pediatric amplification (e.g., The Pediatric Working Group 1996; American Academy of Audiology, 2004). Ongoing research will, therefore, likely always strive to determine the best methods for prescribing the signal processing ch...

NAL-NL2 Empirical Adjustments

“…This investigation confirms, that relative to NAL-NL1, lower overall loudness that is also well below normal overall loudness is achieved with NAL-NL2. According to this investigation, NAL-NL2 prescribed gain generally appears more similar to that prescribed by DSLm[i/o] (Scollie et al, 2005) than that of CAMEQ2-HF (Moore, Glasberg, & Stone, 2010).…”

The Contribution of a Frequency-Compression Hearing Aid to Contralateral Cochlear Implant Performance

“…In their study, several phases were implemented, including: 1) a four-week home trial with conventional hearing aids, 2) a 10-week home trial with frequency compression, and 3) a six-week home trial where the user could select either conventional amplification or frequency compression using multiple memories. Initially, the conventional hearing aids were fit to DSL prescriptive targets (DSL v5: Bagatto et al, 2005;Scollie et al, 2005) and simulated real-ear measures were obtained to verify the accuracy of the fit incorporating individual real ear to coupler differences (RECDs). Next, the frequency-compression hearing aids were fit to provide audibility of high-frequency sounds (e.g., /s/ and /sh/) using listening checks and aided spectra performed by the fitter.…”

Effects of Removing Low-Frequency Electric Information on Speech Perception With Bimodal Hearing

“…The NAL-Revised, Profound fitting formula is another strategy developed specifically for individuals with severe-to-profound HL, which prescribes less low-frequency gain for flat and rising HL configurations and more high-frequency amplification for steeply sloping HL (Byrne, Dillon, Ching, Katsch, & Keidser, 2001). The Desired Sensation Level strategy is another HA fitting rationale that is considered to have a greater emphasis on audibility in that more amplification is prescribed in the high frequencies, particularly for children, given the importance of these sounds for their speech and learning needs (Pittman 2008;Scollie et al, 2005). It may be that the selection of the appropriate HA fitting formula should be determined separately for each individual on the basis of interactions between the CI and HA, as well as degree of HL, age, experience, and other factors.…”