Supra-aural Earphones Research Articles

Effects of Different Auditory Stimuli and Cognitive Tasks on Balance in Healthy Young Adults

Introduction: This study investigated the effect of different auditory stimuli and cognitive tasks on balance in healthy young adults. Methods: Thirty-three participants, aged 23.33 ± 2.43 years, were included in the study. The hearing levels of the participants were determined. Static and dynamic postural stability and limits of stability (LOS) tests were performed in the absence of auditory stimuli, in the presence of spondee word lists at 70 dB(A) and in the presence of spondee+white noise (−6 dB signal-to-noise ratio [SNR]), while auditory stimuli were presented bilaterally with supra-aural headphones. Participants were asked to repeat the words they listened to while performing balance-related tasks. Results: No significant differences between the three conditions were observed in the postural stability and LOS results. Increase in total repetition error was observed as the listening task became more difficult. Conclusion: The presence of auditory stimuli and the cognitive tasks did not cause any changes in the participants’ balance.

Effect of audio-tactile congruence on vibrotactile music enhancement.

Music listening experiences can be enhanced with tactile vibrations. However, it is not known which parameters of the tactile vibration must be congruent with the music to enhance it. Devices that aim to enhance music with tactile vibrations often require coding an acoustic signal into a congruent vibrotactile signal. Therefore, understanding which of these audio-tactile congruences are important is crucial. Participants were presented with a simple sine wave melody through supra-aural headphones and a haptic actuator held between the thumb and forefinger. Incongruent versions of the stimuli were made by randomizing physical parameters of the tactile stimulus independently of the auditory stimulus. Participants were instructed to rate the stimuli against the incongruent stimuli based on preference. It was found making the intensity of the tactile stimulus incongruent with the intensity of the auditory stimulus, as well as misaligning the two modalities in time, had the biggest negative effect on ratings for the melody used. Future vibrotactile music enhancement devices can use time alignment and intensity congruence as a baseline coding strategy, which improved strategies can be tested against.

Estimates of interaural attenuation in children and the implications for masking in clinical audiometry

Objective The aim of this study was to provide estimates of interaural attenuation (IA) in children, under clinical test conditions for supra-aural and insert earphones. Design This was a retrospective review of clinical audiograms for children aged 8 months to 16 years. Study sample There were between 2 and 21 subjects, depending on the transducer and stimulus frequency. Results For insert earphones, younger age groups had smaller IA estimates (mean 60 dB, minimum 40 dB) compared to older children (mean 78 dB, minimum 60 dB). The insert IA estimates for older children were similar to published adult IA data. There was no significant effect of age on the children’s estimated IA for supra-aural earphones. Conclusions Under the clinical conditions of this study, cross-hearing should be considered when the difference between the better ear and poorer ear not-masked air conduction thresholds are ≥ 40 dB for inserts with foam tips in children under 13 years. Smaller estimates of IA in younger children compared to older children may be due to difficulties achieving deep insertion of foam tips in smaller ears and less cooperative subjects under these conditions. Limitations of the study, including lack of bone conduction threshold data, are discussed.

The Impact of Transducer Selection on the Acceptable Noise Level

The aim of this study was to assess the impact of transducer (loudspeaker, supra-aural headphones, and insert earphones) selection on the acceptable noise level (ANL). Thirty young adults with normal hearing who reported difficulty with background noise served as participants. A repeated-measures experimental design was employed. Most comfortable listening level (MCL) and background noise level (BNL) were measured for all participants using three transducers (loudspeaker, supra-aural headphones, and insert earphones). ANL was computed as the difference between the mean MCL and the mean BNL. Analytical statistics revealed that ANL did not differ due to the transducer used. However, there were statistically significant differences found for MCL and BNL across transducers. Results of this study indicate that ANL is not vulnerable to the selection of transducer and that ANLs can be compared across transducer types. Researchers should cautiously interpret findings across studies when discussing the base measures of MCL and BNL as these may be influenced slightly by transducer selection.

Ambient Noise Monitoring during Pure-Tone Audiometry.

There is an increasing need to administer hearing tests outside of sound-attenuating rooms. Maximum permissible ambient noise levels (MPANLs) from published in standards (Occupational Health and Safety Administration [OSHA] 1983; American National Standards Institute [ANSI] S3.1-1999 (R2018)) can be modified to account for the additional attenuation provided by circumaural earphones (relative to supra-aural earphones) that are used for pure-tone audiometry. Ambient noise can influence the results of pure-tone audiometry by elevating thresholds by direct masking and by producing distractions that affect the accuracy of the test. The effects of these distractions have not been studied in relation to pure-tone audiometry in adult listeners. In Part I MPANLs provided by ANSI and OSHA standards are extended to account for the greater attenuation provided by circumaural earphones. Rules ("alerts") were developed taking into account the listeners' thresholds. In Part II effects of distracting noise on pure-tone thresholds are reported. In Part I MPANLs two standards were modified for circumaural earphones by adding the additional attenuation provided by three circumaural earphones (relative to supra-aural earphones). A set of rules ("alerts") is provided for identifying masking effects from ambient noise in a variety of conditions (earphone type, threshold elevation, uncovered ear). In Part II the distracting effects of an industrial noise sample on thresholds obtained from five listeners with normal hearing are described. Pure-tone thresholds were measured in quiet and in distracting noise presented at various levels. The effects of the distracting noise on the following variables were measured: time per trial, number of trials required to measure threshold, threshold shift, and perceived distractibility of the noise. Time per trial was unaffected by distracting noise. Number of trials required for threshold, threshold shift, and perceived distractibility increased with distracting noise level. Part I: The modified MPANLs provide more relevant determinations of the potential effects of ambient noise on pure-tone thresholds than the values in the standards. Part II: Distracting noise affects pure-tone threshold measurements in a manner that is different from direct masking. The potential contaminating effect of distracting noise can be measured and reported.

Frequency responses of headphones modulate alpha brain oscillations related to auditory processing

The perception of sound can differ significantly, regardless of its physical properties. The frequency content of a sound can provoke different psychoacoustic effects on humans, and simultaneously, it modulates differently brain oscillations. Audio devices such as headphones are variables that have not been taken into consideration in many studies concerning acoustic therapies, which strongly depend on the transmission means. Headphones become a fundamental key in acoustic treatments since they are responsible for transmitting auditory stimuli. It is known that the frequency response of audio devices can change the frequency content of a signal. However, it is still unknown if their limited (or even inappropriate) functioning could affect acoustic therapy effectiveness. Therefore, the present work aims to analyze alpha (resonance frequency at which neurons decode auditory information) brain oscillations in healthy individuals when listening to the same sound but through different frequency responses of headphones. For this purpose, the frequency responses of three headphone models were firstly obtained: Atvio® supra-aural headphones (ATVIO), Shure® SRH1840 circum-aural headphones (SHURE), and Apple® EarPods® intra-aural headphones (APPLE). The estimated frequency responses showed that ATVIO and APPLE headphones presented a major difference in comparison with an ideal frequency response (same gain at every frequency of the headphone bandwidth, i.e., a flat frequency response). Then, inverse filters on the difference of the responses were implemented. Finally, the alpha brain oscillations of 29 individuals were analyzed while they were listening to pink noise through the filters of the three models. The findings suggested that the three headphones modulated alpha brain oscillations accordingly their frequency response. Namely, mapping of alpha brain oscillations for ATVIO and APPLE headphones reflected lower neural activity associated with decoding of auditory information, possibly due to the loss of gain at different frequencies. In contrast, SHURE headphones, which presented a flatter frequency response, reflected higher neural activity related to decoding and interpretation of acoustic information since frequency response was much less affected.

Structural Modifications of Headphone Front Chamber for Better Frequency Response: Experimental and Simulation Studies

The supra-aural headphone concentrates the sound in the listener’s ears, so the loudspeaker sound is confined to the cavity between the pinna and the headphone casing. It is then directed toward the tympanic membrane through the ear-canal. The high-quality sound requirement of supra-aural headphone on one side and space limitation on the other prompted this research. Similarly, inherent sound leakages from headphone on one side and a need for loud sound on the other also impelled this research. This research proposes headphone design modifications for interaction between sound from the diaphragm’s rear and front side for improved frequency response. The changes attempt to stop the sound from the diaphragm’s rear side to leak to the external surrounding, and it is routed to interact with the sound from the front side of the diaphragm in two distinct ways due to the geometrical/structural modifications of the headphone front cover. Prototypes of three headphones (one traditional and two modified) have been modeled by computer-aided drafting software and fabricated by 3D printing. In parallel, equivalent circuits have been formed for the simulation as per the proposed headphone testing setup. The frequency response measurements of headphones have been done in an anechoic chamber using B&K HATS Type 4128. The simulated and measured responses of headphones demand modification of the equivalent circuit by adding the current-controlled voltage source. The optimum simulated performances of all three headphones with a modified equivalent circuit show an improved agreement with respective measured performances.

The Accuracy of Smartphone Sound Level Meter Applications (SLMAs) in Measuring Sound Levels in Clinical Rooms.

The accuracy of smartphone sound level meter applications (SLMAs) has been investigated with varied results, based on differences in platform, device, app, available features, test stimuli, and methodology. This article determines the accuracy of smartphone SLMAs with and without calibration of external and internal microphones for measuring sound levels in clinical rooms. Quasi-experimental research design comparing the accuracy of two smartphone SLMAs with and without calibration of external and internal microphones. Two iOS-based smartphone SLMAs (NIOSH SLM and SPL Meter) on an iPhone 6S were used with and without calibrated external and internal microphones. Measures included: (1) white noise (WN) stimuli from 20 to 100 dB sound pressure level in a sound-treated test booth and (2) sound levels in quiet in four nonsound-treated clinical rooms and in simulated background sound conditions using music at 45, 55, and 80 dBA. Chi-square analysis was used to determine a significant difference (p ≤ 0.05) in sound measures between the SLMAs and a Type 1 SLM. Measures of WN signals and room sound level measures in quiet and simulated background sound conditions were significantly more accurate at levels ≥ 40 dBA using the SLMAs with calibrated external and internal microphones. However, SLMA measures with and without calibration of external and internal microphones overestimated sound levels < 40 dBA. The SLMAs studied with calibrated external or internal microphones are able to verify the room environment for audiologic screening at 1,000, 2,000, and 4,000 Hz at 20 dB hearing level (American Academy of Audiology and American Speech-Language-Hearing Association) using supra-aural earphones (American National Standards Institute S3.1-1999 [R2018]). However, the tested SLMAs overestimated low-level sound < 40 dBA, even when the external or internal microphones were calibrated. Clinicians are advised to calibrate the microphones prior to using measurement systems involving smartphones and SLMAs to measure room sound levels and to monitor background noise levels throughout the provision of clinical services.

Effects of Self-Generated Noise on Quiet Threshold by Transducer Type in School-Age Children and Adults.

Purpose Low-frequency detection thresholds in quiet vary across transducers. This experiment tested the hypothesis that transducer effects are larger in young children than adults, due to higher levels of self-generated noise in children. Method Listeners were normal-hearing 4.6- to 11.7-year-olds and adults. Warble-tone detection was measured at 125, 250, 500, and 1000 Hz with a sound-field speaker, insert earphones, and supra-aural headphones. Probe microphone recordings measured self-generated noise levels. Results Thresholds were similar across ages for speaker measurements. Transducer effects were larger for children than adults, with mean child-adult threshold differences at 125 Hz of 3.4 dB (insert earphones) and 6.6 dB (supra-aural headphones). Age effects on threshold were broadly consistent with noise levels measured in the ear canal. Conclusions Self-generated noise appears to elevate children's low-frequency thresholds measured with occluding transducers. These effects could be particularly relevant to the diagnosis of minimal and mild hearing loss in children.

Relationship between aided cortical auditory evoked responses and aided behavioral thresholds

ObjectivesThe present study aimed to determine the relationship between aided cortical auditory evoked potentials and aided behavioral thresholds. Secondary aims of the study were to investigate the relationship between age and Cortical Auditory Evoked Potentials latencies, and to analyze the relationship between the /m/, /g/ and /t/ stimuli. MethodTherefore, 20 subjects (4-8 years old) who diagnosed with moderate to severe hearing loss were included in the study. Behavioral pure-tone audiometry was performed using supra-aural earphones. After verification of the settings of hearing aid settings, aided behavioral thresholds were determined in the free field. Aided CAEPs were recorded using the HEARLab system in a sound-treated room. The /m/, /g/, and /t/ speech stimuli were applied with durations of 30, 20, and 30 ms respectively. ResultsA strong correlation was found between aided cortical auditory evoked responses at the level of 55 dB SPL and aided behavioral thresholds in the free field(r=0.86). We showed that the CAEP latencies were not correlated with the age (/m/ stimulus [r=-0.051; p=0.830], /g/ stimulus [r=-0.053; p=0.825], and /t/ stimulus [r=0.121; p=0,610]). The mean latency of the /m/ stimulus at 55 dB SPL intensity was longer than those of the /g/ and /t/ stimuli. ConclusionThe results of the present study demonstrated that the use of the cortical auditory evoked potentials is clinically useful for measuring the hearing aid benefit. The CAEP can predict the aided behavioral thresholds in children with moderate hearing loss.

Validation of clinical techniques for verification of uniform attenuation earplugs

Objective: Uniform attenuation earplugs (UAE) theoretically provide near even attenuation across frequencies when built to a manufacturer’s specifications. Unfortunately, there is no current research available confirming if custom-molded uniform attenuation earplugs (UAE) are made to specifications nor is there guidance available on clinical methods of measuring attenuation of uniform attenuation earplug (UAE) devices. The goal of this study was to evaluate different procedures for UAE verification and to determine the most accurate clinically accessible verification protocol. Design: Attenuation was measured using probe microphone techniques, as well as real-ear attenuation at threshold (REAT) measurements under circumaural earphones, soundfield speakers and supra-aural earphones. Comparisons were made to a reference system created in the laboratory. Study sample: Seventeen adult participants, totaling 30 ears. Results: The results of this study demonstrate that the REAT measured in the soundfield using a narrowband noise stimulus with masking in the contralateral ear is currently the most accurate and widely available method of verifying UAEs. Conclusions: Factoring in clinical efficiency, the authors of this study recommend verifying attenuation levels using a soundfield REAT procedure as best clinical practice. In addition, the data suggests that REAT measurements under circumaural earphones are an acceptable second choice method.

Accuracy of Smartphone Self-Hearing Test Applications Across Frequencies and Earphone Styles in Adults.

The purpose of this study is to evaluate smartphone-based self-hearing test applications (apps) for accuracy in threshold assessment and validity in screening for hearing loss across frequencies and earphone transducer styles. Twenty-two adult participants (10 = normal hearing; 12 = sensorineural hearing loss; n = 44 ears) underwent conventional audiometry and performed 6 self-administered hearing tests using two iPhone-based apps (App 1 = uHear [Version 2.0.2, Unitron]; App 2 = uHearingTest [Version 1.0.3, WooFu Tech, LLC.]) each with 3 different transducers (earbud earphones, supra-aural headphones, circumaural headphones). Hearing sensitivity results using the smartphone apps across frequencies and transducers were compared with conventional audiometry. Differences in accuracy were revealed between the hearing test apps across frequencies and earphone styles. The uHear app using the iPhone standard EarPod earbud earphones was accurate to conventional thresholds (p > .002 with Bonferroni correction) at 1000, 2000, 4000, and 6000 Hz and found valid (81%-100% sensitivity, specificity, positive and negative predictive values) for screening mild or greater hearing loss (> 25 dB HL) at 500, 1000, 2000, 4000, and 6000 Hz. The uHearingTest app was accurate in threshold assessment and determined valid for screening mild or greater hearing loss (> 25 dB HL) using supra-aural headphones at 2000, 4000, and 8000 Hz. Self-hearing test apps can be accurate in hearing threshold assessment and screening for mild or greater hearing loss (> 25 dB HL) when using appropriate transducers. To ensure accuracy, manufacturers should specify earphone model instructions to users of smartphone-based self-hearing test apps.

Prevalence and Pattern of Using Headphones and Its Relationship with Hearing Loss among Students

Background: Noise-induced hearing loss (NIHL) is one of the most important public health problems. There is scant information about NIHL, the prevalence and using patterns of headphones and music player devices in Iran. Objectives: This study aimed to assess the prevalence and using patterns of earphones and investigate the relationship between earphone use and hearing loss in a sample of students from Qazvin University of Medical Sciences (QUMS). Methods: In this cross-sectional study, 890 students were randomly selected using a proportional cluster sampling method in April and May 2015. The students completed a self-administered questionnaire assessing the pattern of their earphone use and hearing loss. Receiver operating characteristic (ROC) curve analysis was used to determine the cut-off point for the questionnaire. Results: The results suggested that 60.2% (95% confidence interval (CI): 56.9 - 66.4) of the students reported a history of hearing loss and hearing impairment and 86.4% (95% CI: 84.0 - 88.5) of the participants reported using an earphone in the past. Most of the participants listened to music on their cell phones (81.7%) and 89.6% of them used headphones for listening to music. The results indicated that 51.3% of those who used earphones used earbud-style earphones, 42.2% used supra-aural earphones, and 6.5% used headphones. Students who used earphones, those who used earphones more frequently during the week, and those who used earphones for more years had higher hearing loss scores compared to other students. Conclusions: Students have a risky pattern of using personal listening devices. The higher hearing loss score among headphone users requires further attention in order to implement interventions to increase students’ awareness and attitude towards the use of headphones.

The acute effect of exposure to noise on cardiovascular parameters in young adults.

Objective: In this study, an experiment was conducted to examine whether noise exposure produced acute changes in cardiovascular responses, and whether these responses differed based on psycho-acoustic parameters to noises of low to high intensity. Methods: Thirty healthy subjects were enrolled. Three industrial noises were binaurally presented with a supra-aural earphone. The sound levels of noise were <55, 75, and 90 dB. Each noise was continued for 20 min and the electrocardiogram was simultaneously recorded. Results: The results showed a statistically significant increase in systolic blood pressure (SBP) at the 90 dB sound level. The study estimated a blood pressure increase of 0.85 mmHg/10 dB and 0.71 mmHg/10 dB in SBP and diastolic blood pressure (DBP), respectively. These results suggest that exposure to noise, particularly high-frequency noise, negatively impacts blood pressure. The tonality and fluctuation strength of noise especially impacts systolic blood pressure. Conclusions: The psycho-acoustic parameters of noise should be considered when evaluating the impact of noise exposure.

Supra-aural transducer-related artifact contributes to overestimation of noise-induced hearing loss.

This study compared the effects of supra-aural and insert receivers on the prevalence of noise-induced hearing loss (NIHL) in young adults. NIHL prevalence was found to be substantially higher when hearing thresholds were obtained with supra-aural compared to insert receivers on the same subjects. Real-ear sound pressure levels at 4000, 6000, and 8000 Hz were the major predictors of notched-audiograms obtained with supra-aural headphones. Distortion-product otoacoustic emissions were not significantly different between ears with and without notched-audiograms obtained with supra-aural headphones. The results demonstrated that supra-aural transducer-related artifacts can mimic a notch-like pattern leading to overestimation of NIHL prevalence.

Effects of self-generated noise on quiet threshold by transducer type in school-age children and adults

This study tested the hypothesis that higher levels of self-generated noise in children results in larger child-adult differences for the detection of low-frequency sounds when testing is conducted using transducers associated with a pronounced occlusion effect. Detection thresholds were measured at 125, 250, 500, and 1000 Hz using standard clinical procedures with supra-aural headphones, insert earphones, or a loudspeaker. Probe microphone recordings were made during testing with each transducer. Listeners were 4.5- to 11-year-olds, and adults. Preliminary results are consistent with the a priori hypothesis. For all listeners, thresholds at 125 and 250 Hz were highest with supra-aural headphones and lowest with free-field presentation. This transducer effect was most pronounced for younger children. Child-adult differences were smaller at 500 and 1000 Hz, an observation consistent with reduced effects of self-generated noise with increasing frequency. Trial-by-trial analysis of probe microphone recordings will be presented.

Out-of-Booth Testing with Noise-canceling Earphones

Out-of-Booth Testing with Noise-canceling Earphones

Ear canal collapse prevalence and associated factors among users of a center of prevention and rehabilitation for disabilities

ABSTRACT Purpose: to investigate the prevalence of the ear canal collapse when using supra-aural earphones and to verify if this event is influenced by sex, age, color of the skin and prominent ear. Methods: the collapse was assessed by a visual inspection after the positioning of a detached cushion, pressured against the external ear. Results: a total of 436 individuals, aged 3 to 97 years, participated in the study. Ear canal collapse was observed in 11.4% of the subjects, being mostly bilateral (90.0%). The prevalence ranged from 6.3% to 36.6% across age groups. Males, aged 65 years or above and presence of prominent ear were independently identified as associated factors for the occurrence of ear canal collapse (p&lt;0.05). Despite a higher prevalence for those self-identified as white skinned when compared to non-whites, the difference was not statistically significant. Conclusion: the ear canal collapse, when supra-aural earphones are used, is more likely to occur in men, in elderly people, and among those with prominent ears. The prevalence of the event in this population raises the necessity of a careful examination, previous to any evaluation using supra-aural earphones.

No correlation between headphone frequency response and retail price

This study quantifies variability of measured headphone response patterns and aims to uncover any correlations between headphone type, retail price, and frequency response. For this purpose, the mean, variance, and covariance of the frequency magnitude responses were analyzed and correlated with headphone type and retail value. The results indicate that neither the measured response nor an attempt to objectively quantify perceived quality is related to price. On average, in-ear headphones have a slightly higher measured bass response than circumaural and supra-aural headphones. Furthermore, in-ear and circumaural headphones have a slightly lower deviation from an assumed target curve than supra-ear models. Ninety percent of the variance across all headphone measurements can be described by a set of six basis functions. The first basis function is similar to published target responses, while the second basis function represents a spectral tilt.

Automated Smartphone Threshold Audiometry: Validity and Time Efficiency

Smartphone-based threshold audiometry with automated testing has the potential to provide affordable access to audiometry in underserved contexts. To validate the threshold version (hearTest) of the validated hearScreen™ smartphone-based application using inexpensive smartphones (Android operating system) and calibrated supra-aural headphones. A repeated measures within-participant study design was employed to compare air-conduction thresholds (0.5-8 kHz) obtained through automated smartphone audiometry to thresholds obtained through conventional audiometry. A total of 95 participants were included in the study. Of these, 30 were adults, who had known bilateral hearing losses of varying degrees (mean age = 59 yr, standard deviation [SD] = 21.8; 56.7% female), and 65 were adolescents (mean age = 16.5 yr, SD = 1.2; 70.8% female), of which 61 had normal hearing and the remaining 4 had mild hearing losses. Threshold comparisons were made between the two test procedures. The Wilcoxon signed-ranked test was used for comparison of threshold correspondence between manual and smartphone thresholds and the paired samples t test was used to compare test time. Within the adult sample, 94.4% of thresholds obtained through smartphone and conventional audiometry corresponded within 10 dB or less. There was no significant difference between smartphone (6.75-min average, SD = 1.5) and conventional audiometry test duration (6.65-min average, SD = 2.5). Within the adolescent sample, 84.7% of thresholds obtained at 0.5, 2, and 4 kHz with hearTest and conventional audiometry corresponded within ≤5 dB. At 1 kHz, 79.3% of the thresholds differed by ≤10 dB. There was a significant difference (p < 0.01) between smartphone (7.09 min, SD = 1.2) and conventional audiometry test duration (3.23 min, SD = 0.6). The hearTest application with calibrated supra-aural headphones provides a cost-effective option to determine valid air-conduction hearing thresholds.