Jessica J. Messersmith

Effect of narrowband noise maskers on increment detection.

The ability to detect a brief increment in intensity in a longer duration stimulus is often used as a measure of the intensity resolution of the auditory system, but it is unclear how listeners perform the task. Early investigators suggested that detection of an increment in intensity was based on the overall energy within the critical band centered on the signal frequency. The use of signal energy falling outside of the critical band is often limited by introducing a noise masker. Recent findings indicate that envelope fluctuations in a masker can increase thresholds in increment detection, suggesting a decision process based on envelope modulation. A modulation‐based decision device was evaluated by adding irregularity to the envelope of an increment detection task via noise maskers of varying bandwidth. Results indicate that thresholds for detection of an increment in the intensity of a pure tone increase with increasing bandwidth for an on‐frequency noise masker, but are unchanged by an off‐frequency ...

The relative weighting of energy and envelope‐modulation cues in increment detection.

Recent findings suggest that listeners primarily rely on envelope‐modulation cues rather than energy cues in an increment detection task, where one of the two sounds contains a brief increment in intensity in a longer duration tone. The relative contributions of energy and envelope‐modulation cues in increment detection were evaluated in six normal‐hearing young adults. The detection thresholds for a 20 ms increment added in the middle of a 420 ms pedestal of either 500 or 4000 Hz were obtained as a function of pedestal level. On‐frequency or off‐frequency maskers were either 30‐ or 150‐Hz wide random‐phase Gaussian noise (RPN) or low‐noise noise (LNN), centered either at 500 or 4000 Hz. The envelope fluctuation in LNN is minimal compared to that in RPN. The detection thresholds were greater in RPN than LNN in on‐frequency, but not in off‐frequency masking conditions. The detection thresholds increased at the wider masker bandwidth. Results suggest that listeners may rely on a decision process that is bas...

Legislation Impacting Audiology and the Provision of Audiological Services: A Review of Legislation Across the United States

PURPOSE The purpose of this review was to investigate the legislation about the provision of audiology services. Specifically, the goal of the review was to investigate the similarities and differences in legislation regarding the identification of, and audiology services provided to, children with hearing loss. METHOD A systematic review was conducted to collect state-specific legislation regarding the audiology licensure requirements, requirements about the identification and management of children with hearing loss, and insurance coverage regulations. Compiled data were analyzed for similarities and differences between state regulations and legislature. RESULTS All states require audiologists to hold licensure; however, many differences exist between the requirements of acquiring and maintaining the license. Some states regulate the identification and management of children with hearing loss, whereas others do not. Additionally, states differ in their regulation of services provided to children with hearing loss, who can provide these services, and what is covered by insurance. CONCLUSION It is critical for audiologists to understand the requirements of their state in the provision of audiology services. Specifically, it is important for audiologists to understand how the laws may impact the services they provide to children with hearing loss.

Cochlear Implantation for Children and Adults with Severe-to-Profound Hearing Loss

Cochlear implants (CIs) have proven to be a useful treatment option for individuals with severe-to-profound hearing loss by providing improved access to ones surrounding auditory environment. CIs differ from traditional acoustic amplification by providing information to the auditory system via electrical stimulation. Both postlingually deafened adults and prelingually deafened children can benefit from a CI; however, outcomes with a CI can vary. Numerous factors can impact performance outcomes with a CI. It is important for the audiologist to understand what factors might play a role and impact performance outcomes with a CI so that they can effectively counsel the recipient and their family, as well as establish appropriate and realistic expectations with a CI. This review article will discuss the CI candidacy process, CI programming and postoperative follow-up care, as well as considerations across the lifespan that may affect performance outcomes with a CI.

Effects of Clinician-Guided Emergent Literacy Intervention Using Interactive Tablet Technology for Preschool Children With Cochlear Implants

The purpose of this study was to investigate if intervention based on a mobile application would improve the print knowledge and vocabulary of preschool children with and without hearing loss. This was a multiple baseline study that included four preschool children. Two of the children had hearing loss and utilized cochlear implants, while the other two had normal hearing. Clinicians utilized a mobile application to facilitate print knowledge (i.e., sound-symbol relationships) and to acquire new vocabulary. By the end of the study, all four children demonstrated improved familiarity with the targeted letter sounds and improved knowledge of the vocabulary words that were utilized during the study. The results of this study indicate that the mobile application, in combination with clinician scaffolding, was an effective tool for facilitating early literacy skills in preschool children. Prior print knowledge and vocabulary development appeared to be stronger indicators of response to treatment than hearing status.

Impact of Aging and Cognition on Hearing Assistive Technology Use

Many factors go into appropriate recommendation and use of hearing assistive technology (HAT). The aging auditory system presents with its own complications and intricacies; there are many types of age-related hearing loss, and it is possible that the underlying cause of hearing loss can significantly impact the recommendations and performance with HATs. The audiologist should take into consideration peripheral and central auditory function when selecting HATs for the aging adult population as well as when selecting appropriate types of technology including personal sound amplification products, hearing aids, cochlear implants, and other assistive technology. The cognitive ability of the patient plays a central role in the recommendations of HAT. It is possible that the use of HATs could mitigate some of the effects of cognitive decline and thus should be considered as early as possible. Assessment of ability and appropriate recommendations are crucial to consistent use of HAT devices.

Reduction in High-Frequency Hearing Aid Gain Can Improve Performance in Patients With Contralateral Cochlear Implant: A Pilot Study

PURPOSE The purpose of this study was to determine whether an alternate fitting strategy, specifically adjustment to gains in a hearing aid (HA), would improve performance in patients who experienced poorer performance in the bimodal condition when the HA was fit to traditional targets. METHOD This study was a retrospective chart review from a local clinic population seen during a 6-month period. Participants included 6 users of bimodal stimulation. Two performed poorer in the cochlear implant (CI) + HA condition than in the CI-only condition. One individual performed higher in the bimodal condition, but the overall performance was low. Three age range-matched users whose performance increased when the HA was used in conjunction with a CI were also included. The HA gain was reduced beyond 2000 Hz. Speech perception scores were obtained pre- and postmodification to the HA fitting. RESULTS All listeners whose HA was programmed using the modified approach demonstrated improved speech perception scores with the modified HA fit in the bimodal condition when compared with the traditional HA fit in the bimodal condition. CONCLUSION Modifications to gains above 2000 Hz in the HA may improve performance for bimodal listeners who perform more poorly in the bimodal condition when the HA is fit to traditional targets.

The effect of narrow-band noise maskers on increment detection

It is often assumed that listeners detect an increment in the intensity of a pure tone by detecting an increase in the energy falling within the critical band centered on the signal frequency. A noise masker can be used to limit the use of signal energy falling outside of the critical band, but facets of the noise may impact increment detection beyond this intended purpose. The current study evaluated the impact of envelope fluctuation in a noise masker on thresholds for detection of an increment. Thresholds were obtained for detection of an increment in the intensity of a 0.25- or 4-kHz pedestal in quiet and in the presence of noise of varying bandwidth. Results indicate that thresholds for detection of an increment in the intensity of a pure tone increase with increasing bandwidth for an on-frequency noise masker, but are unchanged by an off-frequency noise masker. Neither a model that includes a modulation-filter-bank analysis of envelope modulation nor a model based on discrimination of spectral patterns can account for all aspects of the observed data.

Observed variability in d′ for yes‐no and two‐interval forced choice procedures

The sampling distribution of d′ estimates can be determined from knowledge of the true d′ and the number of trials per estimate [J. Miller, Percept. Psychophys. 58, 65–72 (1996)]. Five subjects were tested in a fixed‐level intensity discrimination task to obtain estimates of the observed variance of d′ for both the yes‐no and two‐interval forced‐choice (2IFC) procedures over a wide range of d′ values. The stimuli were 2‐kHz sinusoids, 300 ms in duration with 10‐ms ramps, with differences in intensity ranging from 0.1 to 4.9 dB, centered on 70 dB SPL. An estimate of d′ was computed for each of ten 100‐trial blocks at each intensity difference for each procedure. Psychometric functions, based on 14 000 trials per function, were well fitted using intensity differences expressed in units of ΔL and were steeper for 2IFC than for yes‐no. The variance of d′ estimates exceeded the variance of the sampling distribution by a factor of 2.1 for yes‐no and a factor of 3.1 for 2IFC, with learning effects contributin...

A comparison of intensity discrimination and increment detection as measures of intensity resolution

Intensity resolution can be measured by determining the threshold for discrimination of two stimuli differing only in intensity or by determining the threshold for detection of an increment in a longer duration stimulus. Better resolution has been reported for the latter task, but the results are inconsistent across conditions and subjects. In the present study, data were obtained for the two tasks in a range of conditions for 12 adult subjects with normal hearing. Thresholds for intensity discrimination and increment detection were measured for a 4000‐Hz tone presented at 20, 40, 60, or 80 dB SPL, using a two‐track adaptive procedure that estimated levels required for 71% and 89% correct. The increment was 20, 40, 80, or 160 ms in duration. The pedestal was either the same duration as the increment or was 200 ms longer, centered on the increment. Thresholds expressed in units of delta L were more uniform across subjects and conditions for increment detection than for intensity discrimination. Thresholds ...