Calibration Force Levels for Bone Conduction Vibrators

1977 ◽  
Vol 20 (4) ◽  
pp. 653-660 ◽  
Author(s):  
Bradley L. Billings ◽  
Margaret Winter
Keyword(s):  
Young Adults ◽  
Pure Tone ◽  
Sound Pressure ◽  
Bone Conduction ◽  
Normal Hearing ◽  
National Standards ◽  
International Electrotechnical Commission ◽  
Bone Conduction Threshold ◽  
Air Conduction ◽  
Good Agreement

Two bone conduction vibrators (Radioear B71 and B72) and a headband (Radioear P-3333) have been developed to meet specifications of both the International Electrotechnical Commission and the American National Standards Institute. Pure-tone thresholds for air conduction and bone conduction were obtained from 24 normal-hearing young adults at audiometric frequencies between 250 and 4000 Hz. Results of this study are in good agreement with the standard air conduction threshold sound pressure levels (ANSI) and with bone conduction threshold force levels reported in the literature.

The Variability of Occluded and Unoccluded Bone-Conduction Thresholds

1967 ◽  
Vol 10 (2) ◽  
pp. 232-249 ◽  
Author(s):  
Donald Dirks ◽  
John G. Swindeman
Keyword(s):  
Young Adults ◽  
Bone Conduction ◽  
Normal Hearing ◽  
Previous Experience ◽  
Basic Design ◽  
Test Frequency ◽  
Final Experiment ◽  
Occlusion Effect ◽  
Air Conduction

A series of three experiments of similar basic design was performed on individuals with normal hearing to compare the variability associated with occluded and unoccluded bone-conduction thresholds. Estimates of threshold were obtained at each test frequency for air conduction, unoccluded bone conduction, and occluded bone conduction stimuli. Eleven young adults participated in Experiment I. Their ears were occluded by TDH-39 earphones encased in MX41/AR cushions. In Experiment II 11 young adults were tested with a Grason-Stadler 001 circumaural cushion replacing the MX41/AR cushion. Two types of occluders were compared in Experiment III, using nine subjects with previous experience in Bekesy tracing. The variability of the occluded bone-conduction thresholds was either similar or less than that observed during the unoccluded measurements. The variability of the occlusion effect itself was comparable or less than the variability of the unoccluded or occluded bone-conduction thresholds. The source of the variability stemmed largely from differences between individuals rather than from test-retest variability. Although the variability of the occluded thresholds was reduced slightly when the circumaural cushion was used as compared to the supra-aural cushion, the results of the final experiment did not completely support the earlier finding.

scholarly journals Audiogram in Response to Stimulation Delivered to Fluid Applied to the External Meatus

2020 ◽  
Vol 24 (2) ◽  
pp. 79-84
Author(s):  
Miriam Geal-Dor ◽  
Shai Chordekar ◽  
Cahtia Adelman ◽  
Michal Kaufmann-Yehezkely ◽  
Haim Sohmer
Keyword(s):  
Soft Tissue ◽  
Inner Ear ◽  
Pure Tone ◽  
Bone Conduction ◽  
External Auditory Meatus ◽  
Normal Hearing ◽  
External Meatus ◽  
Transmission Pathways ◽  
Air Conduction

Background and Objectives: Hearing can be elicited in response to vibratory stimuli delivered to fluid in the external auditory meatus. To obtain a complete audiogram in subjects with normal hearing in response to pure tone vibratory stimuli delivered to fluid applied to the external meatus.Subjects and Methods: Pure tone vibratory stimuli in the audiometric range from 0.25 to 6.0 kHz were delivered to fluid applied to the external meatus of eight participants with normal hearing (15 dB or better) using a rod attached to a standard clinical bone vibrator. The fluid thresholds obtained were compared to the air conduction (AC), bone conduction (BC; mastoid), and soft tissue conduction (STC; neck) thresholds in the same subjects.Results: Fluid stimulation thresholds were obtained at every frequency in each subject. The fluid and STC (neck) audiograms sloped down at higher frequencies, while the AC and BC audiograms were flat. It is likely that the fluid stimulation audiograms did not involve AC mechanisms or even, possibly, osseous BC mechanisms.Conclusions: The thresholds elicited in response to the fluid in the meatus likely reflect a form of STC and may result from excitation of the inner ear by the vibrations induced in the fluid. The sloping fluid audiograms may reflect transmission pathways that are less effective at higher frequencies.

scholarly journals Vibrational and Acoustical Characteristics of Ear Pinna Simulators That Differ in Hardness

2021 ◽  
Vol 11 (3) ◽  
pp. 327-334
Author(s):  
Ryota Shimokura ◽  
Tadashi Nishimura ◽  
Hiroshi Hosoi
Keyword(s):  
External Auditory Canal ◽  
Sound Pressure ◽  
Bone Conduction ◽  
Calibration Method ◽  
Vibration Acceleration ◽  
Spectral Peaks ◽  
Ear Cartilage ◽  
A Current ◽  
Air Conduction ◽  
Dominant Frequencies

Because cartilage conduction—the transmission of sound via the aural cartilage—has different auditory pathways from well-known air and bone conduction, how the output volume in the external auditory canal is stimulated remains unknown. To develop a simulator approximating the conduction of sound in ear cartilage, the vibrations of the pinna and sound in the external auditory canal were measured using pinna simulators made of silicon rubbers of different hardness (A40, A20, A10, A5, A0) as measured by a durometer. The same procedure, as well as a current calibration method for air conduction devices, was applied to an existing pinna simulator, the Head and Torso Simulator (hardness A5). The levels for vibration acceleration and sound pressure from these pinna simulators show spectral peaks at dominant frequencies (below 1.5 kHz) for the conduction of sound in cartilage. These peaks were likely to move to lower frequencies as hardness decreases. On approaching the hardness of actual aural cartilage (A10 to A20), the simulated levels for vibration acceleration and sound pressure approximated the measurements of human ears. The adjustment of the hardness used in pinna simulators is an important factor in simulating accurately the conduction of sound in cartilage.

Automated Audiometry in Quiet and Simulated Exam Room Noise for Listeners with Normal Hearing and Impaired Hearing

2021 ◽  
Author(s):  
Brianna N. Bean ◽  
Richard A. Roberts ◽  
Erin M. Picou ◽  
Gina P. Angley ◽  
Amanda J. Edwards
Keyword(s):  
Pure Tone ◽  
Local Area ◽  
Normal Hearing ◽  
Automated Testing ◽  
Impaired Hearing ◽  
Step Size ◽  
Low Level ◽  
Exam Room ◽  
Controlled Environments ◽  
Air Conduction

Abstract Background Up to 80% of audiograms could be automated which would allow more time for provision of specialty services. Ideally, automated audiometers would provide accurate results for listeners with impaired hearing as well as normal hearing. Additionally, accurate results should be provided both in controlled environments like a sound-attenuating room but also in test environments that may support greater application when sound-attenuating rooms are unavailable. Otokiosk is an iOS-based system that has been available for clinical use, but there are not yet any published validation studies using this product. Purpose The purpose of this project was to complete a validation study on the OtoKiosk automated audiometry system in quiet and in low-level noise, for listeners with normal hearing and for listeners with impaired hearing. Research Design Pure tone air conduction thresholds were obtained for each participant for three randomized conditions: standard audiometry, automated testing in quiet, and automated testing in noise. Noise, when present, was 35 dBA overall and was designed to emulate an empty medical exam room. Study Sample Participants consisted of 11 adults with hearing loss and 15 adults with normal hearing recruited from the local area. Data Collection and Analysis Thresholds were measured at 500, 1000, 2000, and 4000 Hz using the Otokiosk system that incorporates a modified Hughson-Westlake method. Results were analyzed using descriptive statistics and also by a linear mixed-effects model to compare thresholds obtained in each condition. Results Across condition and participant group 73.6% of thresholds measured with OtoKiosk were within ± 5 dB of the conventionally measured thresholds; 92.8% were within ± 10 dB. On average, differences between tests were small. Pairwise comparisons revealed thresholds were ∼3.5–4 dB better with conventional audiometry than with the mobile application in quiet and in noise. Noise did not affect thresholds measured with OtoKiosk. Conclusions The OtoKiosk automated hearing test measured pure tone air conduction thresholds from 500 - 4000 Hz at slightly higher thresholds than conventional audiometry, but less than the smallest typical 5 dB clinical step-size. Our results suggest OtoKiosk is a reasonable solution for sound booths and exam rooms with low-level background noise.

Multiple Auditory Steady-State Responses to Bone-Conduction Stimuli in Adults with Normal Hearing

2005 ◽  
Vol 16 (03) ◽  
pp. 172-183 ◽  
Author(s):  
Susan A. Small ◽  
David R. Stapells
Keyword(s):  
Steady State ◽  
Bone Conduction ◽  
Normal Hearing ◽  
Phase Delay ◽  
Research System ◽  
Steady State Responses ◽  
Auditory Steady State Responses ◽  
State Responses ◽  
Single Versus ◽  
Air Conduction

ASSR thresholds to bone-conduction stimuli were determined in 10 adults with normal hearing using mastoid placement of the bone oscillator. ASSRs to 0–50 dB HL bone-conduction stimuli and to 30–60 dB HL air-conduction stimuli were compared. The effect of alternating stimulus polarity on air- and bone-conduction ASSRs was also investigated. Stimuli were bone- and air-conduction amplitude-modulated tones (500–4000 Hz carrier frequencies, modulated at 77–101 Hz). ASSRs were recorded using the Rotman MASTER research system. Mean (1SD) bone-conduction ASSR thresholds were 22(11), 26(13), 18(8), and 18(11) dB HL for 500, 1000, 2000, and 4000 Hz, respectively. Except for a steeper slope at 500 Hz, ASSR intensity-amplitude functions for binaural bone- and air-conduction stimuli showed the same slopes; intensity-phase-delay functions were steeper at 1000 Hz for ASSRs to bone-conduction stimuli. ASSR amplitudes and phases did not differ for single- versus alternated-stimulus polarities for both bone- and air-conduction stimuli. The steeper amplitude slope for ASSRs to 500 Hz stimuli may reflect a nonauditory contribution to the ASSR.

scholarly journals Hearing gain after myringoplasty in relation to the size of tympanic membrane perforation

2020 ◽  
Vol 25 (1) ◽  
pp. 54-59
Author(s):  
Sutanu Kumar Mondal ◽  
Ashim Kumar Biswas ◽  
Md Mahmudul Huq ◽  
Md Hasan Ali ◽  
Md Kamruzzaman ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Tympanic Membrane ◽  
Bone Conduction ◽  
Tympanic Membrane Perforation ◽  
Medium Size ◽  
Hearing Gain ◽  
Bone Conduction Threshold ◽  
Large Size ◽  
Membrane Perforation ◽  
Air Conduction

Objectives: To assess hearing gain after successful myringoplasty in relation to the size of tympanic membrane perforation. Methods: This cross-sectional study was done in the department of otolaryngology and head neck surgery, BSMMU, Sahbag, Dhaka during the period of January 2009 to December 2010.A total of 60 patients were under went myringoplasty operation after taking detailed history, clinical examination and investigation. Preoperative and postoperative hearing assessment was done. Analysed data presented by various tables, graphics and figures. Results: In case of small size perforation preoperative mean bone conduction threshold was 7.66 dB, mean air conduction threshold was 34.14 dB and mean air bone gap was 26.48 dB. In case of medium size perforation preoperative mean bone conduction threshold was 9.61 dB, mean air conduction threshold was 44.48 dB. Mean air bone gap was 34.87 dB. In case of large size perforation preoperative mean bone conduction threshold was 13.12 dB, mean air conduction threshold was 59 dB, and mean air bone gap was 45.88 dB. Hearing loss increases with increasing size of perforation. Ahmed and Rahim (1979) showed in the study that hearing loss increases with increasing the size of the perforation which was relevant in the study. After myringoplasty post-operative mean air bone gap was 21.24 dB in small size, 21.74 dB in medium sized and 24 dB in large size. From the record improvement of mean air bone gap or hearing gain was 5.24 dB in small size perforation respectively. The different of air bone gap closure between small and medium size perforation was statistically significant by unpaired’ test. Conclusion: Hearing gain after myringoplasty is better in large size perforation. Bangladesh J Otorhinolaryngol; April 2019; 25(1): 54-59

Normal Brief-Tone Bone-Conduction Behavioral Thresholds Using the B-71 Transducer: Three Occlusion Conditions

2003 ◽  
Vol 14 (10) ◽  
pp. 556-562 ◽  
Author(s):  
Susan A. Small ◽  
David R. Stapells
Keyword(s):  
Auditory Brainstem Response ◽  
Pure Tone ◽  
Bone Conduction ◽  
Auditory Brainstem ◽  
Behavioral Thresholds ◽  
Brainstem Response ◽  
Occlusion Effect ◽  
Response Testing ◽  
Brief Tones ◽  
Air Conduction

Behavioral thresholds were measured from 31 adults with normal hearing for 500, 1000, 2000, and 4000 Hz brief tones presented using a B-71 bone oscillator. Three occlusion conditions were assessed: ears unoccluded, one ear occluded, and both ears occluded. Mean threshold force levels were 67, 54, 49, and 41 dB re:1μN peak-to-peak equivalent in the unoccluded condition for 500, 1000, 2000, and 4000 Hz, respectively (corrected for air-conduction pure-tone thresholds). A significant occlusion effect was observed for 500 and 1000 Hz stimuli. These thresholds may be used as the 0 dB nHL (normalhearing level) for brief-tone bone-conduction stimuli for auditory brainstem response testing.

scholarly journals A cross sectional study of hearing thresholds in medical students

2019 ◽  
Vol 5 (2) ◽  
pp. 434
Author(s):  
V. M. Hemlata Katiyar ◽  
D. Elango ◽  
Vincent Prasanna
Keyword(s):  
Young Adults ◽  
Medical Students ◽  
Noise Exposure ◽  
Bone Conduction ◽  
Normal Hearing ◽  
Early Screening ◽  
Cross Sectional ◽  
Hearing Thresholds ◽  
Significant Difference ◽  
The Right

<p class="abstract"><strong>Background:</strong> The hearing thresholds of young adults with no known hearing loss or noise exposure is expected to be closer to 0 dB HL, though with the increasing usage of recreational noise through personal amplification devices there is shift in thresholds noted. Some studies have highlighted the effect of these devices on the hearing thresholds and a general shift of thresholds towards 25 dB. Objective was to determine the audiometric thresholds of a screened sample of medical students with presumed normal hearing.</p><p class="abstract"><strong>Methods:</strong> A total of 103 medical students in the age group of 20 to 23 years were screened and subjected to PTA. The Pure tone average was calculated for air conduction (AC) and bone conduction (BC) separately and also for high frequencies (HF). The average for the female students was compared with that of male students. The right ear average was compared with that of left ear.  </p><p class="abstract"><strong>Results:</strong> There was a statistically significant difference with higher thresholds for males in BC and HF, however the difference in AC was not significant. Between the right and left ears, there was statistically significant elevation observed in BC average in the right ear, but no significant difference was found in the HF and AC thresholds.</p><p class="abstract"><strong>Conclusions:</strong> There is evidence of thresholds especially BC, shifting more towards 25 dB HL in young adults considered to have normal hearing. Early screening will help in identifying this and prevent further elevation by judicious use of mobile phones, personal music players and personal listening devices.</p>

scholarly journals A study to assess hearing improvement after fat graft myringoplasty

2021 ◽  
Vol 7 (2) ◽  
pp. 303
Author(s):  
Nupur Midha ◽  
Gurbax Singh ◽  
Rachna Dhingra ◽  
Rajwant Kaur
Keyword(s):  
Pure Tone ◽  
Bone Conduction ◽  
Pure Tone Audiometry ◽  
Threshold Level ◽  
Fat Graft ◽  
Hearing Improvement ◽  
Suppurative Otitis Media ◽  
Bone Conduction Threshold ◽  
Tympanic Membrane Perforations ◽  
Number Of Patients

<p class="abstract"><strong>Background:</strong> Tympanic membrane perforations result mainly from infectious and traumatic etiologies. Postoperative outcomes of reconstructive surgeries of hearing mechanism have routinely been assessed by take up rates and air bone gap closure on pure tone testing. The present study was conducted to assess hearing improvement after fat graft myringoplasty.</p><p class="abstract"><strong>Methods:</strong> The present prospective study was conducted from 1<sup>st</sup> January 2017 to 30<sup>th</sup> June 2018. The study population consists of patients of age 18 to 60 years. The subjects with safe or tubotympanic type of chronic suppurative otitis media with small dry central perforation or perforation of the pars tensa less than 3 mm were included in the study. Pure tone audiometry (PTA) was consigned to an audiologist who was blind to the study. Air conduction threshold level was measured at frequencies 0.25 to 8 kHz and bone conduction threshold level was measured at frequencies 0.5 to 4 kHz; average air bone gap of each patient was calculated preoperatively and postoperatively at one and three months at the frequencies 500 Hz, 1000 Hz and 2000 Hz.  </p><p class="abstract"><strong>Results:</strong> Among 30 patients, 15 (50.00%) had pre-operative bone conduction threshold in the range of 0-10 dB HL and rest 15 (50.00%) had between 11-20 dB HL. Majority of them i.e. 20 had post-operative air bone gap in the range of 0-10 dB HL whereas 02 had pre op air bone gap in this range, followed by 07 with air bone gap in the range of 11-20 dB HL as compared to 18 in the pre op and 03 in the range of 21-30 dB HL as compared to 10 in the pre op. Paired t test reveals results are significant.</p><p class="abstract"><strong>Conclusions:</strong> Postoperative audiometry at the end of 1 month revealed majority i.e. 14 had air bone gap in range of 0-10 dB HL thus showing improvement in hearing. Postoperative audiometry at the end of 3 months revealed maximum number of patients i.e. 20 in the range of 0-10 dB HL which showed further improvement in hearing in the form of decrease in air bone gap.</p><p class="Default"> </p>

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