OBJECTIVETo investigate the effective way to test 4-year-old children's ability of sound localization in the horizontal plane.

METHODSUsing minimum audible angle (MAA) measure procedure on the basis of conditioned play audiometry, sound localization test was conducted for 4-year-old children at 0 degrees , +/- 45 degrees , +/- 90 degrees , +/- 135 degrees and 180 degrees standard positions in the horizontal plane.

RESULTSThe outcome of sound localization test for 4-year-old children separately were: MAA (0 degrees ) = (3.80 +/- 0.71) degrees , MAA (-45 degrees ) = (7.70 +/- 1.27) degrees , MAA (45 degrees ) = (7.10 +/- 1.39) degrees , MAA (-90 degrees ) = (8.15 +/- 2.38) degrees , MAA (90 degrees ) = (7.61 +/- 2.47) degrees , MAA (-135 degrees ) = (8.85 +/- 2.70) degrees , MAA (135 degrees ) = (8.30 +/- 1.42) degrees , MAA (180 degrees ) = (5.20 +/- 1.27) degrees . The MAA of eight standard positions were less than 10 degrees , and the MAA (0 degrees ) was the smallest one.

CONCLUSIONSOur findings suggest that MAA test procedure on the basis of conditioned play audiometry could be used to evaluate the ability of sound localization in 4-year-old children.

No abstract available.
Hearing Loss, Conductive ; Sound Localization

Auditory Perception ; Child ; Humans ; Sound Localization

This systematic review evaluated the impact of using digital pinna-cue preserving technologies (PPT) on front/back sound localization for adult hearing aid users. Two peer-reviewed studies and two non-peer-reviewed studies were included. Lab-based and self-report outcomes were both assessed. The overall findings suggested that PPT was superior to omni-directional and full directional settings in a relatively quiet, well-controlled laboratory environment but not in the real world. However, observed individual differences in self-report measures suggested that PPT was potentially beneficial to certain hearing aid users. PPT candidacy was discussed and the importance of a pre-fitting interview/consultation was emphasized to assist clinicians in making a solid evidence-based and cost-effectiveness decision when prescribing hearing aids to adults with hearing impairment.
Adult* ; Hearing Aids* ; Hearing Loss ; Humans ; Individuality ; Sound Localization

Exposure of humans to unusual spaces is effective to observe the adaptive strategy for an environment. Though adaptation to such spaces has been typically tested with vision, little has been examined about adaptation to left–right reversed audition, partially due to the apparatus for adaptation. Thus, it is unclear if the adaptive effects reach early auditory processing. Here, we constructed a left–right reversed stereophonic system using only wearable devices and asked two participants to wear it for 4 weeks. Every week, the magnetoencephalographic responses were measured under the selective reaction time task, where they immediately distinguished between sounds delivered to either the left or the right ear with the index finger on the compatible or incompatible side. The constructed system showed high performance in sound localization and achieved gradual reduction of a feeling of strangeness. The N1m intensities for the response-compatible sounds tended to be larger than those for the response-incompatible sounds until the third week but decreased on the fourth week, which correlated with the initially shorter and longer reaction times for the compatible and incompatible conditions, respectively. In the second week, disruption of the auditory-motor connectivity was observed with the largest N1m intensities and the longest reaction times, irrespective of compatibility. In conclusion, we successfully produced a high-quality space of left–right reversed audition using our system. The results suggest that a 4-week exposure to the reversed audition causes optimization of the auditory-motor coordination according to the new rule, which eventually results in the modulation of early auditory processing.
Ear ; Fingers ; Hearing* ; Humans ; Magnetoencephalography* ; Reaction Time ; Sound Localization

PURPOSE: Spatial hearing refers to the ability to understand speech and identify sounds in various environments. We assessed the validity of the Korean version of the Spatial Hearing Questionnaire (K-SHQ). MATERIALS AND METHODS: We performed forward translation of the original English SHQ to Korean and backward translation from the Korean to English. Forty-eight patients who were able to read and understand Korean and received a score of 24 or higher on the Mini-Mental Status Examination were included in the study. Patients underwent pure tone audiometry (PTA) using a standard protocol and completed the K-SHQ. Internal consistency was evaluated using Cronbach's alpha, and factor analysis was performed to prove reliability. Construct validity was tested by comparing K-SHQ scores from patients with normal hearing to those with hearing impairment. Scores were compared between subjects with unilateral or bilateral hearing loss and between symmetrical and asymmetrical hearing impairment. RESULTS: Cronbach's alpha showed good internal consistency (0.982). Two factors were identified by factor analysis: There was a significant difference in K-SHQ scores for patients with normal hearing compared to those with hearing impairment. Patients with asymmetric hearing impairment had higher K-SHQ scores than those with symmetric hearing impairment. This is related to a lower threshold of PTA in the better ear of subjects. The hearing ability of the better ear is correlated with K-SHQ score. CONCLUSION: The K-SHQ is a reliable and valid tool with which to assess spatial hearing in patients who speak and read Korean. K-SHQ score reflects the severity and symmetry of hearing impairment.
Audiometry ; Ear ; Hearing Loss* ; Hearing Loss, Bilateral ; Hearing* ; Humans ; Sound Localization

BACKGROUND AND OBJECTIVES: Sound localization in subjects with normal hearing is done by recognition of interaural difference of time, intensity and phase of sound source. Individuals with unilateral hearing losses, deprived of the binaural cues, are expected to have difficulty in localizing sound. The purpose of the research is to investigate the sound localizing ability in subjects with unilateral hearing losses to localize sound in horizontal plane by comparing with normal control group, and to know the effects of age, gender, stimulus type and hearing level. MATERIALS: Two groups of subjects participated in this study. The first group consisted of 60 normal hearing adults, in each age groups of 10 subjects, ranging from teens to sixties. The second group consisted of 50 subjects with unilateral hearing losses. METHODS: Sound localization ability was assessed by means of an array of eight loudspeakers positioned at the azimuth of 45 degrees each in the horizontal plane at a distance of 100 cm from the subject. The stimuli consisted of speech noise, narrow band noise centered at 500 Hz and 4000 Hz, pure tone of 500 Hz and 4000 Hz at the level of 45 dB HL for 5 seconds. RESULTS: 1) Speech noise was the most easily detected stimulus (p<0.001). 2) The age and gender did not affect significantly to the ability to localize sound (p>0.05). 3) The localization errors for speech noise increased significantly as hearing threshold increased in patients with unilateral hearing losses (p<0.001). CONCLUSION: The results suggest that speech noise is the most easily detected stimulus in directional discrimination test and that the ability of sound localization is degraded as hearing threshold is increased for patients with unilateral hearing losses.
Adolescent ; Adult ; Cues ; Discrimination (Psychology) ; Hearing Loss* ; Hearing Loss, Unilateral* ; Hearing* ; Humans ; Noise ; Sound Localization*

Visually impaired people face many inconveniences because of the loss of vision. Therefore, scientists are trying to design various guidance systems for improving the lives of the blind. Based on sensory substitution, auditory guidance has become an interesting topic in the field of biomedical engineering. In this paper, we made a state-of-technique review of the auditory guidance system. Although there have been many technical challenges, the auditory guidance system would be a useful alternative for the visually impaired people.
Acoustics ; Auditory Perception ; Biomedical Engineering ; Equipment Design ; Humans ; Sensory Aids ; Software ; Sound Localization ; Visual Perception ; Visually Impaired Persons ; rehabilitation

It is acknowledged that implantable bone conduction hearing aids such as a bone anchored hearing aid provide benefit and satisfaction to patients with unilateral hearing loss in terms of sound localization and speech perception under noise circumstances. This review paper introduces current models of the implantable bone conduction hearing aids, their candidacy, brief surgical procedures, and general audiological examinations. A table summary was used for nine published research papers which have very similar results by three points, i.e., no change in ability of sound localization, better performance of Hearing-In-Noise Test, and improved satisfaction of sound quality using questionnaires after the implantation. Unfortunately, systematic fitting strategy for users of the implantable bone conduction hearing aids has not been either studied or developed yet. Futhermore, there is no scientific based approach of reason why the implantation has no benefit in sound localization but still provides better performance for speech perception in noise. In conclusion, specific and effective fitting strategy of the current implantable bone conduction hearing aids should be developed and also support effect of the implantation with sensitivity and specificity for both clinicians and patients while accompanying their advanced technology.
Bone Conduction ; Hearing Aids ; Hearing Loss, Unilateral ; Humans ; Noise ; Sensitivity and Specificity ; Sound Localization ; Speech Perception ; Suture Anchors

The incidence of single-sided deafness（SSD） is increasing year by year. Due to the hearing defects of one ear, the ability of sound localization, speech recognition in noise, and quality of life of patients with single-sided deafness will be affected to varying degrees. This article reviews the intervention effects of different types of bone conduction hearing aids in patients with single-sided deafness and asymmetric hearing loss, and the differences of intervention effects between bone conduction hearing aids, contralateral routing of signal（CROS） aids, and cochlea implant（CI）, to provide a reference for the auditory intervention and clinical treatment of single-sided deafness and asymmetric hearing loss.
Humans ; Quality of Life ; Bone Conduction ; Hearing Loss, Unilateral/therapy* ; Speech Perception ; Hearing Aids ; Hearing Loss ; Sound Localization ; Deafness ; Treatment Outcome