Catherine V. Palmer

The functionally and physiologically plastic adult auditory system

The potential for functional and underlying physiological change in the adult auditory system is examined through review and evaluation of several sets of literature including auditory deprivation and recovery, auditory learning after hearing aid fitting, auditory abilities of normal listeners exposed to masking noise, and neural plasticity in the sensory and motor systems of animals. This tutorial review is meant for the reader who may be interested in auditory learning and who would like to have a summary and evaluation of the various findings to date. The focus of the review is the effect that various findings of auditory learning may have on hearing aid fitting and selection.

Amplification With Digital Noise Reduction and the Perception of Annoying and Aversive Sounds

Hearing aid users report difficulties using their hearing aids in noisy environments. Problems include understanding speech, loudness discomfort, and annoyance with background noise. Digital noise reduction algorithms have been promoted as a method to solve speech understanding and comfort in noise problems. Research has failed to find improved speech understanding in noise. Little is known about how digital noise reduction affects noise annoyance and aversiveness. The goals of this investigation were to determine how a specific digital noise reduction system affects hearing aid users’ perception of noise annoyance and aversiveness and to compare their perceptions to those of normal-hearing listeners. Ratings of noise annoyance and of aversiveness were obtained from 49 participants with moderate sensorineural hearing loss before fitting and after 3 weeks of hearing aid use. Findings were compared to measures obtained from normal-hearing listeners. Perceived annoyance and aversiveness increased with amplification. Annoyance and aversiveness with the hearing aid approximated normal perception. The results of this investigation suggest the need for counseling patients about realistic expectations related to annoyance and aversiveness of sounds at the time of hearing aid fitting.

Accuracy of hearing aid use time as reported by experienced hearing aid wearers.

OBJECTIVE The purpose of this study was to investigate the relationship between the amount of time that a person reports wearing his or her hearing aid and the actual time that the hearing aid is worn. Although use time data are used in the analysis and interpretation of investigations concerned with auditory perceptual learning and with user satisfaction, the accuracy of self-reported use time has not been fully investigated. DESIGN The experimental and control group were fit with a hearing aid that has the capability of storing use time data for later analysis. The experimental group was told that the self-reported use time would be verified with a computer analysis of the hearing aid that provides the actual use time. The control group was not informed of the use time validation procedure. The agreement between self-reported and actual use time was compared statistically between groups (knowledge of validation versus no knowledge of validation). RESULTS The experimental group provided accurate self-reported use time whereas the control group showed a significant difference between actual use time and self-reported use time. CONCLUSIONS The results may assist in the interpretation of results of previous investigations that have depended on self-reported use time and in the design of future investigations. For the clinician, the results indicate that relying on a patients self-reported hearing aid use time for documentation of satisfaction or signal processing preference may be misleading.

Hearing and Listening in a Typical Classroom

In the past, many educational audiologists dedicated the majority of their time to assessing the hearing status of students and providing listening solutions to those students with hearing loss. Mo...

Goals and expectations of the hearing aid fitting.

For the child, meeting communication needs is an ongoing process. The DIAL, the Pediatric Hearing Demand, Ability, and Need Profile, and the Family Expectation Worksheet should streamline this process and provide the information needed to create functional auditory goals considering what normally hearing children accomplish while accounting for the specific needs and abilities of the individual child. In addition, this protocol should provide the tools to create ongoing evaluation, treatment, and documentation of accomplishments through the use of assistive technology and communication strategies. These tools are meant to empower both the clinician and family in order to work as partners in the process of functional auditory development that leads to secure, self-reliant, socially active children who happen to have hearing loss. This set of tools provides the information needed for the clinician to identify what auditory situations demand solutions. Creating the solutions is another topic all together. It is only meaningful to define these situations if the clinician is prepared to create auditory and nonauditory solutions. These solutions may involve hearing aid technology (hearing aid features, telecoils, direct audio input, behind-the-ear/FM combinations), clever communication strategies, or advanced assistive technology (alerting systems, telephone amplifiers, etc.). If not in a position to provide the total package of these intervention services, begin with the hearing aid fitting and refer the patient to a cooperating facility to complete the package. It is essential that both facilities discuss the needed hearing aid options in order to allow coupling to recommended assistive technology (Palmer, 1996). The clinician will find that keeping up with the solutions demands a large time commitment. Valuable information can be found in scientific and trade journals as well as in the exhibit halls of major audiology conferences. The Interactive Assistive Device Product Locator computer program provides a comprehensive database of current assistive technology which can help familiarize the clinician with the range of technological solutions available (Palmer and Garstecki, 1990; Palmer and Rauterkus, 1992). Perhaps, most importantly, the clinician should be ready to ask hearing aid manufacturers for specific information regarding the coupling abilities of their hearing aids to various assistive devices. If a satisfactory answer is not forthcoming, work with a manufacturer who appreciates the need for hearing aids that couple successfully with assistive technology.

Comparison of two hearing aid receiver-amplifier combinations using sound quality judgments

Sound quality judgments were obtained on two binaural pairs of laboratory hearing aids with similar battery drain. One pair had a traditional low-current-drain “starved Class A” output stage. The other had a new (at the time) “Class D” output stage. Speech and music reproduction was rated, for seven input levels between 70 and 100 dB SPL, on an overall quality scale by juries of normal-hearing and hearing-impaired subjects. The same subjects also were asked to assign a dollar value to each condition by answering the question “What would you pay for a hearing aid that sounded like that?” Both subject groups rated the hearing aids with the Class D output stage as having superior sound quality across a variety of input levels and test materials, consistent with objective distortion measurements. On the average, each one-percentage point increase in sound quality rating corresponded to a

A Contemporary Review of Hearing Aids

6.75 increase in perceived value in these experiments.

The Effect of Decreased Audibility on MMSE Performance: A Measure Commonly Used for Diagnosing Dementia.

A contemporary review of hearing aids is provided with a focus on current styles of amplification devices, the goals of a hearing aid fitting and the signal processing schemes that allow the clinician to meet these goals, and the need to couple outside devices to hearing aids. A variety of new features available on hearing aids that improve the listeners experience with amplification are described. Some future challenges in hearing aid design and hearing evaluation are presented.

Analysis of counted behaviors in a single-subject design : Modeling of hearing-aid intervention in hearing-impaired patients with Alzheimer's disease

BACKGROUND Hearing loss and dementia are both prevalent in late adulthood. The most common test used to determine cognitive status in late adulthood, the Mini-Mental State Examination (MMSE), is presented face to face, usually in the context of the physicians office in the presence of background noise. Despite the problems of hearing loss and cognitive problems in late life, there is an absence of evidence linking hearing-related deficits to performance on the MMSE and dementia diagnoses. PURPOSE This study examined the effect of decreased audibility on performance on the MMSE. RESEARCH DESIGN A between-subjects design was implemented. Participants were randomly assigned to one of five degrees of simulated hearing loss conditions and were blinded to condition assignment. STUDY SAMPLE One hundred and twenty-five young normal-hearing participants were randomized into five conditions of varying degrees of simulated hearing loss. DATA COLLECTION AND ANALYSIS Performance on the MMSE was scored and cognitive status was categorized based on the scores. Analysis of variance with conditions as a between-subjects factor was conducted with post hoc multiple comparisons to determine the effect of audibility on performance. RESULTS Reduced audibility significantly affected performance on the MMSE in a sample of young adults, resulting in greater apparent cognitive deficits as audibility decreased. CONCLUSIONS Apparent cognitive deficits based on MMSE scores obtained in test conditions in which audibility is reduced could result in incorrectly identified cognitive loss if clinicians are not alert to hearing loss when patients are evaluated. Furthermore, health care providers should be cautious when using family report of cognitive impairment to diagnose dementia without accounting for hearing loss because the impression of family members may be based on misinterpretation of the effects of hearing loss.

Quality-of-life technology for vision and hearing loss [Highlights of Recent Developments and Current Challenges in Technology]

Clinical procedures related to patients with Alzheimers Disease (AD) largely fail to address the patients hearing. Given the challenges of this population, unconventional indicators of treatment efficacy may be required. Palmer et al (1999) reported on caregiver-tracked behaviors as outcome measures for hearing aid intervention. Using these data, hearing aid use and subsequent behavior was modeled as a first-order dynamic system, characterized by responses following an exponential time course. The results of such modeling suggest predictable outcomes of hearing aid intervention, or at least useful parameters of quantification (e.g. time-constant and steady-state response), permitting critical assessment of effects of intervention on negative behaviors versus hearing aid use, comparisons among behaviors, and/or comparisons of hearing-aid-use patterns and behavior counts among patients. Use in this and other difficult-to-test populations warrant further study to evaluate clinical efficacy of the analysis described.