PubMed Health⌕ Search

Biomedical subjects

Francis Kuk

Publications and source records attributed to Francis Kuk.

8 recordsLinked to original sources
PubMed2005

Performance of a fully adaptive directional microphone to signals presented from various azimuths.

The signal-to-noise ratio advantage of a directional microphone is achieved by reducing the sensitivity of the microphone to sounds from the sides and back. A fully adaptive directional microphone (one that automatically switches between an omnidirectional mode and various directional polar patterns) may allow the achievement of signal-to-noise (SNR) improvement with minimal loss on audibility to sounds that originate from the sides and back. To demonstrate such possibilities, this study compared the soundfield aided thresholds, speech in quiet at different input levels, and speech in noise performance of 17 hearing-impaired participants under three microphone modes (omnidirectional, fixed hypercardioid, and fully [or automatic] adaptive) as the stimuli were presented from 0 degrees to 180 degrees in 45 degrees intervals. The results showed a significant azimuth effect only with the fixed directional microphone. In quiet, the fully adaptive microphone performed similarly as the omnidirectional microphone at all frequencies, input levels, and azimuths. In noise, the fully adaptive microphone achieved similar SNR improvement as the fixed directional microphone. Clinical implications of the results of this study were discussed.

Acoustic Stimulation↗
PubMed2005

Vent configurations on subjective and objective occlusion effect.

The current study reexamined the effect of vent diameters on objective and subjective occlusion effect (OE) while minimizing two possible sources of variability. Nine hearing-impaired participants with primarily a high-frequency hearing loss were evaluated. Laser shell-making technology was used to make ear inserts of completely-in-the-canal (CIC) hearing aids for the study. This was to minimize any potential slit leakage from the inserts. The vent dimensions were systematically altered during the study. Participants sustained /i/ for 5 sec, and the real-ear occluded response was measured with a custom-made program that performed frequency averaging to reduce response variability. Participants also repeated the phrase "Baby Jeannie is teeny tiny" and rated their own voice. The results showed a systematic change in the objective OE and subjective ratings of OE as the vent diameter was modified. Furthermore, a significant correlation was seen between subjective rating and objective occlusion effect.

Acoustic Stimulation↗
PubMed2005

Real-world performance of a reverse-horn vent.

The present study compared differences in subjective and objective performance in completely-in-the-canal (CIC) hearing aids with conventional uniform 1.5 mm parallel vents and another with a reverse horn vent where the diameter increased from 1.5 mm on the lateral faceplate to 3 mm on the medial opening of the hearing aid. Nine hearing-impaired persons with a high-frequency hearing loss participated. The test battery included unaided in situ thresholds, amount of available gain before feedback, speech in quiet, speech in noise (HINT), subjective ratings of hollowness and tolerance, objective measures of the occlusion effect, and real-ear aided response. Results showed less available gain before feedback but less occlusion effect for subjective ratings and objective measures with the reverse horn vent. This type of vent design may be useful to increase the effective vent diameter of custom (including CIC) hearing aids.

Aged↗
PubMed2003

Reconsidering the concept of the aided threshold for nonlinear hearing AIDS.

The aided threshold (and functional gain) has been discussed in the context of linear hearing aids since the early 1960s. The use of nonlinear hearing aids, however, could change the meaningfulness of this verification tool because of their unique characteristics. The interpretation of the aided threshold (and functional gain) as it pertains to linear and nonlinear hearing aids is reviewed. Also discussed are the ideas of an optimal aided threshold, factors that may affect its magnitude, and a comparison between functional gain and insertion gain measures. Finally, how to improve the accuracy of the aided thresholds (and functional gain) through the use of in-situ unaided threshold measurements is discussed.

Journal Article↗
PubMed2002

Factors ensuring consistent audibility in pediatric hearing aid fitting.

Ensuring consistent audibility is an important objective when fitting hearing aids to children. This article reviews the factors that could affect the audibility of the speech signals to children. These factors range from a precise determination of the child's hearing loss to an accurate specification of gain in the chosen hearing aids. In addition, hearing aid technology and features such as multichannel processing, directional microphones, and feedback cancellation that could affect the achievement of consistent audibility are reviewed.

Child↗
PubMedDate not supplied

Managing an "own voice" problem that has an amplifier origin.

The complaint from hearing aid wearers of hollowness in the sound of their voice is typically associated with excessive low-frequency sound pressure level (SPL) in the ear canal. Increasing the vent diameter and/or reducing the gain in the low frequency would typically minimize this complaint. This paper reports on a case where the origin of hollowness was insufficient low-frequency gain compared to a previous hearing aid fitting. It describes the systematic process that was followed in uncovering the origin of the patient's hollowness complaint. Clinicians might follow a similar objective approach in their fine-tuning process to resolve wearer complaints.

Aged↗