Sound Field Testing Research Articles

Investigating the Utility of a Compact Loudspeaker Array for Audiometric Testing.

This project addressed the uses of a loudspeaker array for audiometric measurements. It sought to evaluate a prototype compact array in terms of the reliability of test results across sound booths. A seven-loudspeaker array was developed to deliver sounds from -60° to +60° on an arc with a radius of 0.5 m. The system was equipped with a head position sensing system to maintain the listener's head near the optimal test position. Three array systems were distributed to each of the two test sites for within-subject assessments of booth equivalence on tests of sound localization, speech reception in noise, and threshold detection. A total of 36 subjects participated, 18 at each test site. Results showed excellent interbooth consistency on tests of sound localization using speech and noise signals, including conditions in which one or both ears were covered with a muff. Booth consistency was also excellent on sound field threshold measurements for detecting quasi-diffuse noise bands. Nonequivalence was observed in some cases of speech-in-noise tests, particularly with a small one-person booth. Acoustic analyses of in situ loudspeaker responses indicated that some of the nonequivalent comparisons on speech-in-noise tests could be traced to the effects of reflections. Overall, the results demonstrate the utility and reliability of a compact array for the assessment of localization ability, speech reception in noise, and sound field thresholds. However, the results indicate that researchers and clinicians should be aware of the reflection effects that can influence the results of sound field tests in which signal and noise levels from separate loudspeakers are critical.

Studying the influence of cold-core mesoscale ocean eddies on sound propagation based on the parabolic equation method

Mesoscale vorticity is an important factor that affects the non-uniform horizontal and vertical distribution of hydrologic elements in the ocean. In this paper, temperature and salinity data from measured mesoscale cold-core eddies during a voyage within a certain sea area are studied, and a synchronous sound field test was conducted on the mesoscale vorticity. Based on the temperature and salinity data, the parabolic equation (PE) method was selected to predict the acoustic field, and the results were compared with the measured propagation loss data of the acoustic field to verify the accuracy and effectiveness of the PE model. The underwater sound propagation characteristics in the mesoscale cold-core eddy environment were then analyzed using the temperature and salinity data retrieved from the voyage. It was found that the convergence area of the acoustic field gradually dispersed with an increase in the depth of the sound source. In a mesoscale eddy environment, when sound waves propagate from inside to outside the eddy, the presence of a cold-core eddy causes the convergence area to shift toward the edge of the eddy, and the deviation gradually decreases with an increase in the depth of the sound source.

A Feasible Sound Field Measurement in ENT Clinics for Contralateral Routing of Signals Hearing Aids: A Pilot Study

Background and Objectives The hearing in noise test (HINT) or sound localization test (SLT) is used as the standardized assessment for contralateral routing of signals (CROS) and bilateral microphones with contralateral routing of signals (BiCROS) hearing aids (HAs). However, implementing HINT or SLT can be challenging in most ENT clinics. In this study, we propose a new feasible method specifically designed for conducting a sound field hearing test for CROS and BiCROS HA users.Subjects and Method CROS/BiCROS HA users who visited Seoul St. Mary’s hospital between 2019 and 2021 were enrolled for the study. SLT was conducted in a sound-proof room equipped with two speakers positioned at a 45° angle from the patient on each side: noise stimuli were presented to the better ear the headphone patient was wearing while signals were presented to the worse ear via the speakers in the room. To validate the sound field test, a correlation analysis was conducted using the Bern benefit in single-sided deafness and the Korean version of the International Outcome Inventory for Hearing Aids (K-IOI-HA) Questionnaires.Results The aided speech discrimination score was significantly higher in the signal 60 dB HL/masking 50 dB HL condition than 50 dB HL/masking 50 dB HL condition (<i>p</i><0.05). A significant correlation was found between the gain of sound field speech audiometry and the K-IOI-HA questionnaire (<i>p</i><0.05).Conclusion Our novel sound field hearing test for CROS/BiCROS HA users, which presents appropriate noise stimuli via headphones to the better ear, appears to be a feasible approach for CROS/BiCROS HA users.

The sound insulation performance of light wood frame construction floor structure based on phononic crystal theory

The development of timber structures worldwide is rapid and promising. Acoustic insulation is an important metric to measure the quality of occupants' living conditions. Therefore, to effectively improve the harm caused by low-frequency noise of the wood structure floors that people are concerned about, this paper combines the structural characteristics of the light wood frame construction floor with the phononic crystal structure with excellent sound insulation performance and carries out the impedance tube test through the simulation calculation results of COMSOL software. Impedance tube tests and field test studies were also carried out on a two-story light wood frame construction floor in Nanjing, China, to obtain a phononic crystal structure building cover with good sound insulation performance … The conclusion of the study shows that: the G8-40 phononic crystals structure obtained by COMSOL simulation matches with its impedance tube test results, and the effectiveness of its sound insulation performance has been verified by the airborne sound insulation field test; the phononic crystals structure floor has excellent sound insulation performance in the low-frequency band, which can significantly improve the user's living comfort needs and has good engineering application value.

The Effects of Utilizing Cartilage Conduction Hearing Aids among Patients with Conductive Hearing Loss

The cartilage-conduction hearing aid (CC-HA) is a new hearing device that is suitable for use in patients with conductive hearing loss. It has been 5 years since the introduction of the CC-HA. Although the number of users has increased, the CC-HA is not yet widely known. This study examines the effects of CC-HA on patients with conductive hearing loss and investigates factors that affect the willingness to use the device by comparing purchasers and non-purchasers of CC-HA in patients with unilateral conductive hearing loss. Eight patients had bilateral conductive hearing loss, and 35 had unilateral conductive hearing loss. Each patient underwent sound field tests and speech audiometry, and the effects of the CC-HA were compared with those of conventional bone conduction hearing aids (BC-HA). In patients with bilateral conductive hearing loss, the CC-HA was non-inferior to BC-HA. The CC-HA improved the hearing thresholds and speech recognition in patients with unilateral conductive hearing loss. Moreover, in patients with unilateral conductive hearing loss, experiencing the effect of wearing the CC-HA under conditions such as putting noise in the better ear could affect patients’ willingness to use the CC-HA.

Cultural relationship between rural soundscape and space in Hmong villages in Guizhou

The Hmong is one of the oldest ethnic groups in south-western China, and sound plays an important role in their culture. According to the general classification of landscape science, the rural soundscape of Hmong villages is divided into three types: a point soundscape dominated by a single sound source, a line soundscape with a typical Hmong rural village alley space as the sound field interface, and an area soundscape with the Bronze-drum Square, the only open public space of Hmong nationality, as the field. Combined with a sound collection and field test during field investigation, we obtained the characteristics of various rural soundscapes and evaluated the acoustic environment. The results showed that the “point” soundscape of medium- and low-frequency powder shotgun and wooden drum sounds in the unclosed Hmong villages exceed the transmission distance and sound durability. The “line” soundscape utilizes the turning point and envelope of different spaces to increase the acoustic reflection surface and create reverberation, increasing the propagation time and distance of the sound, and emphasizing the directivity of the sound through a long and narrow space. The “surface” soundscape includes the richest medium- and high-frequency-based human voice and music sounds and medium- and low-frequency musical instrument sounds, among others. The values of T30, EDT, and C80 in the sound field, all changed significantly because of the lack of acoustic reflection from the ceiling, through the top opening. Finally, the study reveals the cultural association between rural soundscape and space, which is reflected in the Hmong's “defensive” function and “group” culture. Thus, the Bronze-drum Square sound field does not meet the requirements of the current specification of cultural interpretation, and it is in the participatory Hmong performance mode, centered on drum club group structure.

Resection of Intracochlear Schwannomas With Immediate Cochlear Implantation.

Intralabyrinthine schwannomas, including the intracochlear variety, are rare benign tumors. They can cause a number of symptoms and have the potential to grow to involve other critical structures of the inner ear and skull base. While surgical resection is feasible, there is typically permanent hearing dysfunction as a result of resection and subsequent fibrosis. Here, we present 2 cases of intracochlear schwannomas (ICS) that were successfully resected with simultaneous cochlear implant placement. Patient 1 presented with an intravestibulocochlear schwannoma. This patient underwent a translabyrinthine approach. Endoscopic assistance was used to dissect the tumor from the vestibule and basal turn of the cochlea, through an enlarged round window approach. A cochlear implant was placed via a round window cochleostomy. Patient 2 presented with an intracochlear schwannoma involving the basal and middle turns of the cochlea. The patient underwent a trans-otic approach for resection. A large portion of the cochlear promontory required unroofing for complete exposure of the tumor. A cochlear implant was then placed via a round window cochleostomy. Upon cochlear implant activation, Patient 1's sound field thresholds using the implant were near the normal range of hearing, ranging from 25 to 50 dB HL from 250 to 6000 Hz. Patient 2's 6-month post-operative cochlear implant sound field testing ranged from 20 to 30 dB HL from 250 to 6000 Hz and speech recognition testing revealed 59% on AZ Bio sentences compared to 0% pre-operatively. Simultaneous cochlear implantation after resection of intracochlear schwannomas is safe and successful in restoring hearing. Attention to adequate exposure and endoscopic assistance, when required, allow for gross total resection while minimizing trauma to cochlear structures. In such cases, immediate cochlear implantation allows for hearing rehabilitation before likely cochlear fibrosis can occur.

Speech perception and hearing effort using a new active middle ear implant audio processor

PurposeThe Vibrant Soundbridge (VSB) was introduced in 1996, and the fourth generation of the audio processor recently released. This clinical study evaluates the audiological performance and subjective satisfaction of the new SAMBA 2 audio processor compared to its predecessor, SAMBA.MethodFifteen VSB users tested both audio processors for approximately 3 weeks. Air conduction and bone conduction thresholds and unaided and aided sound field thresholds were measured with both devices. Speech performance in quiet (Freiburg monosyllables) and noise (OLSA) was evaluated as well as subjective listening effort (ACALES) and questionnaire outcomes (SSQ12 and APSQ). In addition, data from 16 subjects with normal hearing were gathered on sound field tests and ACALES.ResultsBoth audio processors showed substantial improvement compared to the unaided condition. The SAMBA and SAMBA 2 had comparable performance in sound filed thresholds, while the SAMBA 2 was significantly better in speech in quiet, speech in noise, reduced listening effort, and improved subjective satisfaction compared with the SAMBA.ConclusionThe SAMBA 2 audio processor, compared to its predecessor SAMBA, offers improved performance throughout the parameters investigated in this study. Patients with a VSB implant would benefit from an upgrade to SAMBA 2.

Test-retest Reliability of the Korean Matrix Sentence-in-noise Recognition in Sound-field Testing Condition

Purpose: This study aimed to measure the test-retest reliability of the Korean Matrix sentence-in-noise test in a sound-field testing condition.Methods: Fifty-five listeners with normal hearing participated. The sound-field speech-in-noise test was administered with a front loudspeaker by presenting noise at a fixed level (65 dB SPL) while adaptively adjusting the sentence level based on the listener’s response. The speech reception thresholds (SRTs) corresponding to 50% sentence-in-noise intelligibility were obtained using speech-shaped noise (SSN), International Collegium of Rehabilitative Audiology (ICRA) noise, and International Speech Test Signal (ISTS) noise. For the test-retest reliability, each subject was tested twice in a 2-week interval. The test-retest reliabilities were judged by the intraclass correlation coefficient (ICC), the minimal detectable change (MDC) values, and Bland-Altman plots.Results: The test-retest reliabilities of the Korean Matrix sentence test were good (ICC, 0.84~0.86) across SSN, ICRA, ISTS noises. The MDC was 0.92 dB SNR for SSN and 2.83 and 2.98 dB SNR for ICRA and ISTS, indicating the random measurement error varied across the types of noise.Conclusion: The Korean Matrix sentence-in-noise test can be used as a reliable tool to assess speech-in-noise intelligibility in sound-field testing condition. Further study across various sessions would strengthen the present finding.

Clinical Trial for Cartilage Conduction Hearing Aid in Indonesia.

Hearing improvement represents one of the may valuable outcomes in microtia and aural atresia reconstruction surgery. Most patients with poor development in their hearing function have had a severe microtia. Conventional methods to improve hearing function are bone conduction and bone anchored hearing aids. Cartilage conduction hearing aids (CCHA) represents a new amplification method. This study assessed the outcomes and evaluated the impact and its safety in the patients with microtia and aural atresia whose hearing dysfunction did not improve after surgery for ear reconstruction in our hospital. Hearing functions were evaluated with pure tone audiometry or sound field testing by behavioral audiometry and speech audiometry before and after CCHA fitting. As a result, there was a significant difference between unaided and aided thresholds (p < 0.001). Speech recognition threshold and speech discrimination level also significantly improved with CCHA. The average functional gains of 14 ears were 26.9 ± 2.3 dB. Almost all parents of the patients reported satisfaction with the performance of CCHA, and daily communication in children with hearing loss also became better than usual.

Fitness assessment in talented football referees: an academy based longitudinal field-study.

This study aim was to profile physical fitness in talented football referees (FR) with performance relevant field-tests across time. Thirty-eight male FR (age 28±1.5 years, height 178±5.1 cm, body mass 69.0±7.34 kg, body fat 17.2±2.87%) were observed for 15 months. Endurance was assessed with the yo-yo intermittent recovery test level 1 (YYIR1) and repeated sprint ability (RSA) with 5×30 m line-sprints with 30 s recovery (5×30 m). Long sprint endurance (LSA) and change of direction ability (COD) evaluated with novel field-tests. FR was tested six times (every three months) during the study. YYIR1 performance showed large increments across testing occasions. Sprint time in the COD largely and significantly decreased across the testing occasions. Very large associations were reported between 5×30 m and LSA tests grand mean (r=0.89, 0.78-0.94, P<0.0001). A nearly perfect (r=0.97, 0.94-0.99, P<0.0001) association was observed between 5×30 m best sprint and 5×30 m grand means. The results of this study revealed ability-related variations in performance across time. The effect of training and competitions on the determinism of physical fitness in refereeing seem plausible. Interestingly, sprint endurance tests shared a very large variance proposing tests interchangeability and mutual physiological demands. This study information provides useful information for the development of sound field-tests batteries in talented FR.

Dynamic sound field audiometry: Static and dynamic spatial hearing tests in the full horizontal plane

Although spatial hearing is of great importance in everyday life, today’s routine audiological test batteries and static test setups assess sound localization, discrimination and tracking abilities rudimentarily and thus provide only a limited interpretation of treatment outcomes regarding spatial hearing performance. To address this limitation, we designed a dynamic sound field test setup and evaluated the sound localization, discrimination and tracking performance of 12 normal-hearing subjects. During testing, participants provided feedback either through a touchpad or through eye tracking. In addition, the influence of head movement on sound-tracking performance was investigated. Our results show that tracking and discrimination performance was significantly better in the frontal azimuth than in the rear azimuth. Particularly good performance was observed across the rear midline in localization, discrimination and tracking tests. As expected, free head movement improved sound-tracking abilities. Furthermore, feedback via gaze detection led to larger tracking errors than feedback via the touchpad. We found statistically significant correlations between the static and dynamic tests, which favor the snapshot theory for auditory motion perception.

Self-focusing Linear Array Sound Field Characteristics and Testing

Self-focusing Linear Array Sound Field Characteristics and Testing

The emergence and prevalence of hearing loss in children with homozygous sickle cell disease

ObjectivesMany children with sickle cell disease (SCD) experience the effect of cochlear insult due to hemolytic anemia and vaso-occlusion that accompanies the disease. As a result, hearing sensitivity eventually decreases. The purpose of this study was to investigate the emergence of hearing loss and the prevalence of such in children with homozygous SCD. MethodsA large pediatric database was utilized to gather audiometric outcomes in children with homozygous SCD. Children were identified by primary diagnosis ICD codes. Demographic and audiometric data was drawn to determine presence, type, degree, and laterality of hearing loss. Hearing loss was defined as an elevated audiometric threshold >15 dB HL for pure tone air conduction audiometry or >20 dB HL minimal response level for sound-field testing. ResultsOne hundred and twenty-eight children were identified. The prevalence of hearing loss ranged from 28.8% to 50.8% depending on the calculation method (i.e., individual vs. ear specific prevalence and any elevated threshold vs. a three-frequency pure tone average). Conductive hearing loss and bilateral loss were most prevalent. The degree of hearing loss ranged from slight to profound. The mean age of identification of sensorineural hearing loss was 9.6 years. ConclusionThe prevalence of hearing loss in children with homozygous SCD is higher than in normal children. Regular hearing assessments of children with SCD is warranted and should be advocated in early infancy and as part of their ongoing care.

A Microscale Linear Phased-Array Ultrasonic Transducer Based on PZT Ceramics.

In this paper, a microscale high-frequency ultrasonic transducer was prepared by combining traditional planar ultrasonic phased-array technology and micro processing technology. The piezoelectric ceramic material PZT was used as the functional material of the transducer. The number of the arrays was 72, the width of each array was 50 μm, the pitch of each array was 70 μm, and the length of each array was 3 mm. The PZT chip was finely ground to a thickness of 130 μm and could reach a frequency of 10 MHz. The experimental platform of micron-scale precision was set up for a beam-forming lateral sound field test and imaging experiment to validate the theoretical analysis. The echo imaging test showed that a mold with a feature size of about 400 μm could be imaged well.

Bonebridge transcutaneous bone conduction implant in children with congenital aural atresia: surgical and audiological outcomes.

To investigate the surgical and audiological outcomes of the Bonebridge transcutaneous bone conduction hearing implant among children with congenital aural atresia. Six children were recruited and underwent Bonebridge transcutaneous bone conduction implant surgery. The patients' audiometric thresholds for air conduction, bone conduction and sound-field tests were assessed pre-operatively and at six months post-operatively. Patients' satisfaction was assessed at six months post-operatively with the Hearing Device Satisfaction Scale. No major complications were reported. Mean aided sound-field thresholds improved post-operatively by more than 30 dB for 0.5-4 kHz (p 0.05). All patients were satisfied (scores were over 90 per cent) with the implant in terms of functional outcome and cosmetic appearance. Bonebridge transcutaneous bone conduction implant surgery is safe and effective among children with congenital aural atresia with conductive hearing loss.

Front- and rear-facing horizontal sound localization results in adults with unilateral hearing loss and normal hearing

Binaural hearing allows listeners to take advantage of auditory cues that are necessary for sound localization. Patients with asymmetric or unilateral hearing loss receive degraded or absent binaural cues and often demonstrate decreased sound localization in the horizontal plane. Given the importance of sound localization for everyday function, there is a need for clinically feasible methods to evaluate localization, particularly as validation of intervention for patients with unilateral hearing loss. The present study compared sound localization results obtained for front-facing and rear-facing soundfield systems and for a rear-facing head related transfer function (HRTF) system in two hearing groups, listeners with normal hearing and those with unilateral hearing loss. Results between the three systems were highly correlated and repeatable. Neither age nor a pure-tone average of 0.5, 1, 2 and 4 kHz correlated with localization performance among normal hearing participants. Among the UHL group, age and onset of severe to profound hearing loss were positively correlated with localization results; length of deafness was negatively correlated. Behavioral chance performance was established for localization with rear-facing HRTF and rear-facing soundfield test systems; group mean results for unilateral hearing loss participants were significantly better than chance. Continued work is needed in developing clinically feasible evaluation methods for patients with asymmetric or unilateral hearing loss, particularly as the effects of treatment options are assessed.

Factors impacting hearing aid performance outcomes for Egyptian hearing impaired children

Despite recent technological advances in the audiologic assessment of children, their hearing aid fitting remains a daunting task. Aims of studyTo assess effectiveness of amplification in children using aided sound field tests and Auditory Behavior in Everyday Life (ABEL) questionnaire and to elucidate factors contributing to poor outcomes.MethodsDetailed medical history, otoscopic examination, basic audiological evaluation, aided sound field tests and ABEL questionnaire for 114 hearing impaired children aged 4–16 years.ResultsCongenital HL considered the commonest cause of HL (55.3%), 36% had unknown cause and 8.8% of HI had acquired cause. Profound loss in 67.5%, severe in 17% and 54.4% of them (54.4%) were fitted around the age of 3 years. Binaural HA in 88.6% and digital type for 61.4%. There were statistically significant differences between unaided and aided values in sound field tests for HI children.Poor performance in direct measures and ABEl in children with congenital and profound degree of hearing loss, better response when they were fitted earlier with digital aids. ABEL scores showed negative correlations with aided tonal sound field test and positive with aided speech discrimination score.ConclusionsInappropriate amplification, late age of fitting with no speech therapy were clinical red flags for poor outcomes. ABEL questionnaire was a valid procedure to assess the hearing aids appropriateness.

Analysis of the effects of uneven sound coverage over a facade during a sound insulation test according to the international standard ISO 16283-3

Building regulations worldwide include specific sections on protection against noise and vibrations, making sound insulation of facades an important part of regulations in many countries. Consequently, sound insulation field tests become important, as a way to certify, or check, if a facade complies with the regulatory requirements. The international standard ISO 16283-3:2016 specifies the procedures and methods to describe the sound insulation of a facade, making the loudspeaker method for the whole facade one of the most widely used because of the advantages it has for practitioners.To make the method consistent, the international standard establishes some constraints, trying to minimize the variation of sound pressure level on the facade. This variation is caused by the directivity of the loudspeaker and the distance from the loudspeaker to the facade, causing an uneven sound coverage over the facade. This paper analyzes and quantifies the solitary influence of facade coverage on the sound insulation determinations in relation to the location of the facade elements. In addition to other influences, the specific location of a small air inlet on a facade can alter the results by up to 4dB, even if the sound coverage complies with the requirements established by the international standard. Finally, an alternative measurement setup is discussed that aims to minimize the negative effect of this phenomenon in an attempt to increase the consistency of the method.

Use of noise cancellation earphones in out-of-booth audiometric evaluations

Objective: To assess the utility of noise cancelation earphones (NCE) in audiometric evaluations. Design: Degree of noise reduction of Bose QuietComfort 15 NCE was assessed through probe-microphone measures and sound-field audiometry. Occlusion effects from NCE were assessed for potential effects on bone-conduction thresholds. Study sample: Twenty participants were tested to determine average occlusion effect values during bone-conduction testing with and without NCE. Noise reduction values of the NCE were assessed on a single subject through probe-microphone measures and sound-field testing. Results: NCE sufficiently reduced ambient noise to levels acceptable for air-conduction testing as well as for bone-conduction testing for most patients when adding minimal adjustment to acceptable levels as outlined by the ANSI S3.1-1999 standard. In addition, NCE did not create a clinically significant change in the occlusion effect for bone-conduction testing. Conclusion: NCE placed over insert earphones provide a sound pressure level at the tympanic membrane that is below ANSI standards for routine air-conduction testing and result in sufficient ambient noise reduction for bone-conduction testing with most patients. There is no clinically significant occlusion effect from NCE during routine bone-conduction audiometry. These findings support the utility of using NCE for offsite audiometric testing.