Search PubMed⌕ Search

Biomedical subjects

J L Punch

Publications and source records attributed to J L Punch.

At least 19 recordsLinked to original sources
PubMed1999

Nonsense-syllable recognition in noise using monaural and binaural listening strategies.

Using a binaurally equipped KEMAR manikin, syllables of the CUNY Nonsense Syllable Test were recorded in sound field at 0-degree azimuth against a background of cafeteria noise at 270-degrees azimuth, at several signal-to-noise (S/N) ratios. The combination of inputs recorded at each ear was delivered to ten normal-hearing (NH) and eight sensorineurally hearing impaired (HI) listeners through insert ear phones to produce five experimental listening conditions: (1) binaural head shadow (HS), in which ear presentation was analogous to the original stimulus recording, (2) binaural favorable (BF), in which the noise-shadowed (right-ear) recording was presented to both ears, (3) monaural favorable (MF), in which the noise-shadowed recording was presented only to the right ear, (4) monoaural unfavorable (MU), in which the noise-unshadowed (left ear) recording was presented only to the left ear, and (5) simulated monoaural aided (SMA), in which the noise-shadowed recording was presented to the right ear and the noise-unshadowed recording--attenuated by 20 dB relative to the HS condition--was presented to the left ear. All main effects (subject type, listening condition, and S/N ratio) were statistically significant. Normal listeners showed 3.3- and 3.2-dB advantages, respectively, due to head-shadow and binaural squelch, over hearing-impaired listeners. Some hearing-impaired listeners performed better under the SMA or BF conditions than under the HS condition. Potential digital signal processing strategies designed to optimize speech understanding under binaurally aided listening conditions are discussed.

Audiometry, Pure-Tone↗
PubMed1996

Development of a hearing performance standard for law enforcement officers.

A hearing performance standard for new police officer candidates in the State of Michigan was developed by a task force consisting of the authors and four members of the Michigan Law Enforcement Officers Training Council. Ratings of the importance of hearing sensitivity and speech intelligibility in performing each of 135 specific job tasks formed the basis for pass-fail criteria. The standard, described in this report, includes specifications for unaided and aided hearing performance, types of hearing assessment measures, hearing measurement procedures, and the appropriate examining professional. The authors believe that the standard provides an appropriate accommodation to hearing-impaired law enforcement officer candidates with respect to The Americans with Disabilities Act.

Hearing↗
PubMed1995

Target-matched insertion gain derived from three different hearing aid selection procedures.

Three hearing aid selection procedures were compared to determine if any one was superior in producing prescribed real-ear insertion gain. For each of three subject groups, 12 in-the-ear style hearing aids with Class D circuitry and similar dispenser controls were ordered from one of three manufacturers. Subject groups were classified based on the type of information included on the hearing aid order form: (1) the subject's audiogram, (2) a three-part matrix specifying the desired maximum output, full-on gain, and frequency response slope of the hearing aid, or (3) the desired 2-cc coupler full-in grain of the hearing aid, based on real-ear coupler difference (RECD) measurements. Following electroacoustic adjustments aimed at approximating a commonly used target insertion gain formula, results revealed no significant differences among any of the three selection procedures with respect to obtaining acceptable insertion gain values.

Adult↗
PubMed1994

Aided listener preferences in laboratory versus real-world environments.

A wearable, fully digital, personal processing unit developed for the study of hearing aid fitting and digital signal-processing techniques was utilized in a preliminary study of hearing aid fitting validation. In a modified single-subject, multiple-baseline control design, 12 hearing-impaired listeners indicated their preferences for monaurally aided frequency response alternatives during an initial laboratory session, a real-world session, and a final laboratory session. Listeners' preferences, based on listening to connected speech, were stored in each environment by the personal processing unit. Within blocks of 3 each, subjects were time-lagged with respect to the number of trials to criterion. Subjects participated in 1 of 4 listening conditions, classified according to laboratory stimulus materials; speech recorded in an audiometric sound room in quiet or noise, and speech recorded in a reverberant room in quiet or noise. When compared with preferences obtained in the initial laboratory session, preferences obtained during the final laboratory session agreed better with those obtained in the real world. Overall, however, preferences under laboratory conditions were only fair predictors of preferences under everyday conditions. Results reveal the potential of harnessing the programming and storage capabilities of digital signal-processing technology in implementing new hearing aid fitting strategies.

Acoustic Stimulation↗
PubMed1992

Prescriptive hearing aid fitting by parameter adjustment and selection.

We describe the rationale for the development of a psychophysical procedure that allows individual listeners to adjust the frequency-gain characteristic of a programmable hearing aid on a unidimensional scale, based on a target-gain reference value. The listener's task is to adjust the frequency response and select the parametric value judged to optimize the intelligibility or quality of speech. Originally described as the Sliding Scale, the procedure has been modified for use in reliability and validity studies of hearing aid fitting at Michigan State University. The modified approach is referred to as the Parameter Adjustment and Selection (PAS) procedure. Primary immediate goals for the procedure are ease of use, high reliability, and rapid clinical administration. The procedure, which may offer potential advantages over a paired-comparison approach, appears to be generally applicable to the fitting of digitally programmable hearing aids.

Auditory Threshold↗
PubMed1991

Evaluation of three strategies for fitting hearing aids binaurally.

Three strategies for evaluating optimum frequency shaping and noise reduction in binaural digital hearing aids were compared in a repeated-measures design, using a new preference-based prescriptive fitting method. These strategies consisted of using preferred frequency shaping and noise reduction values binaurally: (1) based on monaural testing; (2) based on separate evaluations of each ear; and (3) based on evaluation of a second ear while subjects wore an aid programmed with the preferred values in the first ear. Individually preferred characteristics were programmed for 17 hearing-impaired subjects, most of whom exhibited symmetrical sensorineural hearing loss. Each subject was administered intelligibility estimation and midplane localization measurements in the laboratory, as well as a questionnaire survey based on situational listening in the real world. No statistically significant differences in preferences for either frequency shaping or noise reduction were found for the three fitting strategies, suggesting that monaural testing is sufficient in symmetrical cases to provide information for binaural fitting. Related to this finding, differences across binaural conditions were minimal for both intelligibility estimation and localization results. A significant improvement in localization performance under binaural conditions over monaural listening, however, was documented by both the laboratory and the real world data. A strong overall preference for binaural over monaural amplification was also documented under real world conditions.

Adult↗
PubMed1988

The impact of digital technology on the selection and fitting of hearing aids.

The commercial availability of wearable digital hearing aids begins a new era in hearing aid technology. The impact of the introduction of digital technology extends from differences in hardware configuration to changes in the hearing aid fitting process to improvements in the perceptual experience enjoyed by the hearing-impaired individual. In this article, differences among analog, hybrid, and digital technology are reviewed. Performance differences among these technologies are examined in terms of flexibility, size, power consumption, programmability, and signal processing power. Emphasis is placed on the interdependence of hardware technology, signal processing algorithms, and the fitting procedure. The specific advantages of applying digital technology to fitting procedures are discussed. A number of perceptual and nonperceptual factors for the listener and the need to expand the history-taking process to identify performance-oriented patients are discussed. More rapid and reliable tests of patient preferences and speech intelligibility are needed for digital hearing aid fitting procedures.

Acoustics↗
PubMed1988

CROS revisited.

Explore the source record for details and available documents.

Acoustics↗
PubMed1987

Matching commercial hearing aids to prescriptive gain and maximum output requirements.

Insertion gain and saturation sound pressure level (SSPL) characteristics of 71 behind-the-ear hearing aids were evaluated in a computer-assisted analysis as acceptable matches to prescriptive insertion gain and SSPL values derived by a variation of the Prescription of Gain and Output, or POGO, technique (McCandless & Lyregaard, 1983). Stringency criteria in a primary analysis varied from +/- 6 to +/- 16 dB and +/- 2 to +/- 8 dB for gain and SSPL, respectively. Three audiometric contours and associated loudness discomfort levels were used in the simulation. Findings indicated that the relationship between tolerances and the number of aids selected as optimally appropriate varied substantially as a function of audiometric configuration. Minimum gain and SSPL tolerance values of +/- 12 dB and +/- 4 dB, respectively, were required to provide a reasonable choice of instruments for a variety of such configurations. Further analyses shed light on the feasibility of using alternative stringency criteria and on the clinical utility of hearing aid selection using small clinic samples.

Audiometry↗
PubMed1987

Relationships among selected measures of single-channel cochlear implant performance.

Relationships among a number of pre- and postimplant variables measured in 20 adults implanted with a single-channel cochlear implant were examined through a variety of univariate and multivariate statistical techniques. A large number of variables were analyzed to yield information on the relationships between pre- and postimplant performance, and among a variety of postimplant measures. Variables included: age; etiology and nature of deafness; type of implant worn; pre- and postimplant warble tone and speech detection thresholds; postimplant performance on the Monosyllable-Trochee-Spondee (MTS) and Environmental Sounds tests; postimplant electrical thresholds, uncomfortable loudness levels, and dynamic range; I.Q. scores; and postimplant discourse tracking performance with and without the implant. The difference score on the discourse tracking task, representing the auditory advantage over performance with lipreading alone, related substantively to a combination of variables including type of unit worn (Sigma versus Alpha), nature of deafness (progressive versus sudden), and etiology (meningitis versus nonmeningitis). Additionally, MTS and Environmental Sounds test scores were found to relate to one another and to etiology and nature of deafness.

Adolescent↗
PubMed1986

Relative effects of low-frequency amplification on syllable recognition and speech quality.

A moderate-bandwidth master hearing aid was used to study the relationships among low-frequency response, syllable recognition scores, and perceived speech quality. As measured on KEMAR, this hearing aid provided true high-frequency emphasis in all conditions, with three degrees of relative low-frequency de-emphasis. Subjects were 12 listeners with gradually sloping sensorineural hearing loss bilaterally. Contrary to common expectations, increased low-frequency response yielded a substantial enhancement in speech quality under both quiet and babble conditions, as well as a modest improvement in syllable recognition in quiet. Furthermore, low-frequency amplification, as used in this study, resulted in no observable degradation in syllable recognition in the presence of multitalker babble. The findings have clinical implications in the evaluation and selection of hearing aids when optimization of speech quality is desired.

Acoustic Stimulation↗
PubMed1986

Cochlear implant candidate selection.

In recent years there has been an increased acceptance of the cochlear implant as an appropriate sensory aid for selected hearing-impaired individuals with profound losses. With the Food and Drug Administration's release of the 3M/House single channel cochlear implant on November 29, 1984 and the Nucleus 22-channel cochlear implant on October 31, 1985 it is anticipated that many new groups of otologists and audiologists will have direct involvement in this exciting new approach to the management of patients with profound hearing impairments. This report reviews our cochlear implant selection protocol for the severe to profound adult hearing-impaired population.

Adult↗
PubMed1986

Long-term intracochlear implantation in man.

Whether long-term intracochlear implantation and direct electrical stimulation of the acoustic nerve will induce intracochlear bone growth or cause further degeneration of a severely compromised auditory system is an important clinical consideration. Thin-section CT evaluations of the cochleas of six subjects who have used their cochlear implant devices on a daily basis for 3 or more years demonstrated no evidence of osteoneogenesis of the cochlea in the vicinity of the active electrode. No corrosion of the electrode or insulation material was noted on electron microscopy of an explanted electrode system. Electrical threshold and dynamic range measurements have remained stable or even improved during the period of observation. Performance measures using a variety of audiologic tests and speech-tracking scores have demonstrated stability of performance.

Adult↗
PubMed1985

Spondee recognition threshold as a function of set size.

Recognition thresholds for spondaic words were obtained in normal listeners under conditions of varying set size. Six sets of spondees were derived from the 36-word corpus of a Northwestern University recording of CID W-1 spondaic words. One of these sets represented the full list of 36 spondees, whereas the remaining five were comprised of 27, 18, 9, 6, and 3 spondees selected to be homogeneous in level and slope characteristics. Results revealed a systematic and reliable effect wherein mean threshold decreased from 19.1 dB SPL to 12.2 dB SPL as set size was reduced from 36 to 3 spondees. The data are consistent with past research on human information processing in that spondee recognition threshold increased linearly with the number of bits per stimulus.

Adolescent↗
PubMed1982

Tournament strategies in hearing aid selection.

Recently, the elimination tournament has been proposed as an approach to hearing aid selection. In the present study the effects of seeding on the reliability, clinical utility, and validity of the single and double elimination tournament as methods for selecting hearing aids were examined. In an earlier study of round robin tournaments, 12 hearing-impaired subjects were asked to make paired-comparison intelligibility judgments of all possible pairings of eight relatively homogeneous hearing aids. The present study employed these data in a computer-aided simulation of single and double elimination tournaments based on all possible seedings of the eight aids. The results indicated that while group performance was reliable and correlated well with nonsense-syllable identification, the distribution of tournament winners for individual listeners was unreliable and highly dependent on the effects of seeding. These findings were due in part, however, to the similarity of the intelligibility characteristics of the aids employed. Further investigation of the elimination tournament as a method for hearing aid selection is warranted.

Consumer Behavior↗