Chi Lau

Objective: Available data on dichotic listening using tonal Chinese words have been limited, and conflicting results on a right-ear advantage (REA) have been reported. The current study developed a set of Mandarin CV-words based on the Bergen dichotic listening paradigm. Design: The test materials consisted of two sets of stimuli. The English set,...

Objective: Data with regard to the Mandarin dichotic digits test (DDT) are limited, with conflicting results reported between the Mandarin and English DDTs. The current study examined factors that might affect the performance in the Mandarin DDT. Design: The digits were arranged in 3 sets of 20 dichotic pairs; each set comprised 2, 3 or 4 digits in...

Purpose: For Indo-European languages, “speech banana” is widely used to verify the benefits of hearing aids and cochlear implants. As a standardised “Mandarin speech banana” is not available, clinicians in China typically use a non-Mandarin speech banana. However, as Chinese is logographic and tonal, using a non-Mandarin speech banana is inappropri...

The ovarian hormones fluctuate during the menstrual cycle in women. Such fluctuation of sex hormones, in particular estrogen, is believed to affect the central conduction time in auditory function as well as the language lateralization in cognitive function. However, findings are inconsistent. The underlying mechanisms are also unclear. This paper...

Correlation between the change in dichotic-listening scores and the change in central conduction times. (PDF)

ABR wave latency and interpeak conduction time across the menstrual cycle. (PDF)

Ear scores and ear advantage across the menstrual cycle in different attention conditions. (PDF)

Background: The benefits offered by noise reduction (NR) features on a hearing aid had been studied traditionally using test conditions that set the hearing aids into a stable state of performance. While adequate, this approach does not allow the differentiation of two NR algorithms that differ in their timing characteristics (i.e., activation and...

Purpose The aim of this study was to measure the progression of benefits to individuals with tinnitus from providing informational counseling, hearing aids, a brief tinnitus activities treatment and Zen therapy. Method Several magnitude estimation scales and tinnitus handicap scales were administered for the duration of the study to 20 participant...

Conclusion: The ovariectomy in rats does not change their auditory function. However, combining ovariectomy with Cisplatin treatment increases the risk of damaging the auditory function relative to the ototoxic effect caused by Cisplatin alone or ovariectomy alone. Objectives: The auditory benefit from estrogen depends on a number of factors that m...

Objective: The benefits of estrogen for the auditory function of women depend on a number of factors. In this study, we aimed to examine the impact of noise trauma on the auditory function of ovariectomized rats with estrogen deficiency. Materials and methods: Twenty-eight young, female Sprague-Dawley rats were assigned to three groups (OVX+N, O...

Bilateral contralateral routing of signals (BiCROS) hearing aids function to restore audibility of sounds originating from the side of the unaidable ear. However, when speech is presented to the side of the aidable ear and noise to the side of the unaidable ear, a BiCROS arrangement may reduce intelligibility of the speech signal. This negative eff...

Although the benefits of hearing aids are generally recognized for soft- and conversational-level sounds, most studies have reported negative benefits (i.e., poorer aided than unaided performance) at high noise inputs. Advances in digital signal processing such as compression, noise reduction, and directional microphone could improve speech percept...

Hearing-impaired listeners localize sounds better unaided than aided. Wide dynamic range compression circuits operating independently at each ear in bilateral fittings, and microphone positions of different hearing aid styles, have been cited as a reason. Two hearing aid features, inter-ear coordinated compression (IE) and pinna compensation (PC),...

Objective: To evaluate the effectiveness of a home-based and a laboratory-based localization training program. Design: This study examined the effectiveness of a localization training program on improving the localization ability of 15 participants with a mild-to-moderately severe hearing loss. These participants had worn the study hearing aids...

Background: Some evidence exists to support the use of an extended bandwidth (EBW) for those with a relatively mild to moderate degree of hearing loss. The use of frequency lowering is suggested for those with a severe/profound degree of hearing loss. The amplification option for those with a moderately severe hearing loss in the high frequencies...

Background: Today's compression hearing aids with noise reduction systems may not manage transient noises effectively because of the short duration of these sounds compared to the onset times of the compressors and/or noise reduction algorithms. Purpose: The current study was designed to evaluate the effect of a transient noise reduction (TNR) a...

Purpose This study was designed to evaluate the effect of a pinna compensation (PC) algorithm on localization performance in the horizontal plane and speech intelligibility in noise. Method Nine and 18 experienced hearing aid users with bilaterally symmetrical sensorineural hearing loss participated in the localization study and the speech-in-nois...

The maximum power output (MPO) of a hearing aid was typically discussed in the context of avoiding loudness discomfort. However, an MPO that is too low, as in the cases to avoid discomfort for people with a severe loudness tolerance problem and hearing losses that exceed the fitting range of the hearing aids, could negatively affect sound quality a...

Many new processing features in hearing aids have their primary effects on information located in the high frequencies. Speech perception tests that are optimized for evaluating high-frequency processing are needed to adequately study its effects on speech identification. The goal of the current research was to develop a medium for evaluating the e...

Despite a long history of research and commercial efforts, 1 hearing aids with frequency-lowering algorithms have become popular only recently. Their lack of commer-cial success may be attributed in part to the immaturity of analog technology when these devices were intro-duced such that artifacts were plentiful. But insufficient training provided...

Frequency transposition has gained renewed interest in recent years. This type of processing takes sounds in the unaidable high-frequency region and moves them to the lower frequency region. One concern is that the transposed sounds mask or distort the original low-frequency sounds and lead to a poorer performance. On the other hand, experience wit...

Hollow earmolds have become a popular type of earmold used in thin-tube, microsize hearing aid fittings. It is desirable for clinicians to be familiar with their characteristics and limitations. This investigation compared the effects of vent diameter between a traditional solid earmold and a hollow earmold that is used in modern thin-tube hearing...

To investigate the clinical efficacy of linear frequency transposition (LFT) for a group of school-age children. A nonrandomized, within-subject design was implemented to investigate vowel and consonant recognition and fricative articulation of school-age children utilizing this feature. Ten children, aged 6 years and 3 months, to 13 years and 6 mo...

To measure the subjective and objective improvement of speech intelligibility in noise offered by a commercial hearing aid that uses a fully adaptive directional microphone and a noise reduction algorithm that optimizes the Speech Intelligibility Index (SII). Comparison of results on the Hearing in Noise Test (HINT) and the Acceptable Noise Level t...

Children with auditory processing disorders (APD) are described to have a signal-to-noise ratio (SNR) difficulty. Frequency-modulated (FM) systems have been reported to improve this situation. Yet the use of personal amplification that may be more portable has not been attempted. To determine whether personal amplification would result in improveme...

The use of thin-tube open-ear fitting has become increas-ingly popular in the last few years. This type of fitting offers improvements in the wearers' perception of their own voice, especially for people with a mild hearing loss or a high-frequency hearing loss. It also provides an instant fit, is easy to demonstrate, and improves the appearance of...

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 pe...

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)...

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 (SN...

The paired comparison technique can be potentially useful as a means to enhance the prescriptive fitting of hearing aids. Unfortunately, there are no guidelines to suggest how this technique can be used most reliably and efficiently in the clinic. This article reviews how one can apply binomial probability theory to calculate the likelihood of acce...

Thesis (Ph.D.)--University of Hong Kong, 1981. Mode of access: World Wide Web.