Comparing the diagnostic accuracy of audiometric Weber test and tuning fork Weber test in patients with conductive hearing loss

OBJECTIVES

Weber test is typically conducted using tuning forks, but an audiometer can also be used for a similar purpose. Compared to the tuning fork Weber (TFW) test, performing the audiometric Weber (AW) test offers many advantages. Nevertheless, AW and TFW tests' performance compared to pure-tone audiometry (PTA) has yet to be studied. The present study aimed to determine the accuracy and agreement between the AW and TFW tests compared to PTA.

METHODS

In this observational cross-sectional study, 74 participants (aged 12-67 years) with unilateral conductive hearing loss (CHL) or bilateral asymmetrical CHL were enrolled. The TFW test was performed according to the established protocol at 256 and 512 Hz. For the AW test, the bone vibrator was placed in the middle of the forehead, where 250 and 500 Hz frequencies were tested. TF and AW test results were then compared with the expected lateralization from the respective PTA results.

RESULTS

At 256 Hz (or 250 Hz), the overall accuracy values of TFW and AW tests were 81.1% and 86.5%, respectively. At 512 Hz (or 500 Hz), the overall accuracy results of TFW and AW tests were 85.1% and 82.4%, respectively. In addition, the kappa statistics revealed substantial agreements between the two tests and PTA (k = .63-.72).

CONCLUSION

Both AW and TFW tests are reasonably accurate in assessing patients with CHL. It is recommended for audiologists to perform the simple AW test to verify incomplete or questionable audiograms that are commonly encountered in clinical practice.

LEVEL OF EVIDENCE

Level 3b.

Rinne Test Results: How Badly Can We Be Mistaken?

Objective

To establish the extent to which sound amplitudes delivered by a vibrating tuning fork change around its long axis and to evaluate whether such differences in amplitude might change the results of the Rinne test.

Study Design

Experimental measurements.

Setting

Laboratory setting.

Methods

Setup I: a vibrating tuning fork was handheld and manually rotated around its long axis next to a sound recording device (the simulated ear) in order to record sound amplitude data at a full range of angles relative to the device; files were split into segments in which sound amplitude changed: A (from a maximum to a minimum) and B (from a minimum to a maximum). Setup II: a vibrating tuning fork was machine-rotated, and the angle of rotation, along with the sound amplitude, was automatically recorded through a single full rotation.

Results

The angles of 0° and 180° (which equate to the established best practice in Rinne testing) were associated with the highest sound amplitudes. All other angles decreased sound amplitude. The greatest decrease in amplitude was recorded at 51° and 130°. This difference ranged from 9.8 to 34.7 dB, depending on the initial amplitude.

Conclusion

The outcome of a Rinne test can be affected if attention is not paid to the precise angle at which the tuning fork is held relative to the ear. The potential of this effect will be greater when high background noise or patient hearing loss requires that the tuning fork be vigorously excited to obtain high sound amplitudes.

Validation of a smartphone-based Rinne test to detect an air-bone gap

Objective

To validate a smartphone-based Rinne test employing the vibration application of mobile telephones.

Study design

Prospective controlled clinical study.

Setting

Tertiary referral medical center.

Methods

Twenty consecutive patients hospitalized in the otolaryngology department of a tertiary medical center due to unilateral hearing loss (HL study group), and 30 consecutive inpatients on the same ward who had no otological history (controls) were enrolled. Each participant underwent the traditional 512 Hz tuning fork-based Rinne test, as well as a smartphone-based Rinne test by means of a single uncovered smartphone with a vibration application. The test results were compared to those of formal audiometry.

Results

The overall agreement between the traditional Rinne test and the smartphone-based test was 98%. The Sensitivity was 85% for both tests, specificity was 90% and 93% for smartphone and tuning fork tests, respectively. The smartphone-based Rinne test could correctly discriminate between patients with an air–bone gap ≥ 25 dB at 512 Hz from patients with a lower or no air–bone gap at 512 Hz. The smartphone-based Rinne could not evaluate two patients with a moderately severe/severe sensorineural hearing loss due to their inability to detect the vibrations.

Conclusion

A smartphone-based Rinne test was validated for the detection of an air–bone gap ≥ 25 dB at 512 Hz in the clinical setting. The validity of patient-operated smartphone-based Rinne test awaits further study.

Level of evidence

2B.

Contralateral occlusion test: The effect of external ear canal occlusion on predicting conductive hearing loss

INTRODUCTION AND OBJECTIVES

The contralateral occlusion test (COT) has the potential to allow the quantitative evaluation of unilateral conductive hearing loss. The purpose of this study was to determine the accuracy of the test in predicting the degree of hearing loss.

MATERIALS AND METHODS

Fifty-three subjects with unilateral conductive hearing loss were recruited from an otolaryngology department of a tertiary hospital. The COT was performed using 128, 256, 512, 1024 and 2048Hz tuning forks with the non-affected ear canal totally occluded to determine lateralization. Pure-tone audiometry was performed to establish the presence and degree of the air-bone gap (ABG) and the pure-tone average (PTA). The tuning fork responses were correlated with the ABG and the PTA to determine their accuracy.

RESULTS

The COT showed a better association between hearing loss and the lateralization response using the 512Hz tuning fork (p=0.001). The sensitivity of the 512Hz fork in detecting a PTA of at least 35.6dB was 94.6% and the specificity was 75.0% for a positive predictive value of 89.7% and a negative predictive value of 85.7%, assuming a pretest prevalence of 69.8%.

CONCLUSIONS

The overall accuracy of the COT in predicting the degree of unilateral conductive hearing loss was significant. The COT had significant power in one direction: if lateralization to the affected ear occurred, it was almost certain evidence of a moderate or severe conductive hearing loss.

Diagnostic Accuracy of Tuning Fork Tests for Hearing Loss: A Systematic Review

Objective

(1) To determine the diagnostic accuracy of tuning fork tests (TFTs; Weber and Rinne) for assessment of hearing loss as compared with standard audiometry. (2) To identify the audiometric threshold at which TFTs transition from normal to abnormal, thus indicating the presence of hearing loss.

Data Sources

PubMed, Ovid Medline, EMBASE, Web of Science, Cochrane, and Scopus and manual bibliographic searches.

Review Methods

A systematic review of studies reporting TFT accuracy was performed according to a standardized protocol. Two independent evaluators corroborated the extracted data and assessed risk of bias.

Results

Seventeen studies with 3158 participants, including adults and children, met inclusion criteria. The sensitivity and specificity of the Rinne test for detecting conductive hearing loss ranged from 43% to 91% and 50% to 100%, respectively, for a 256-Hz fork and from 16% to 87% and 55% to 100% for a 512-Hz fork. The audiometric thresholds at which tests transition from normal to abnormal ranged from 13 to 40 dB of conductive hearing loss for the Rinne test and from 2.5 to 4 dB of asymmetry for the Weber test. Significant heterogeneity in TFT methods and audiometric thresholds to define hearing loss precluded meta-analysis. There is high risk of bias in patient selection for a majority of the studies.

Conclusion

Variability exists in the reported test accuracy measurements of TFTs for clinical screening, surgical candidacy assessments, and estimation of hearing loss severity. Clinicians should remain mindful of these differences and optimize these techniques in specific clinical applications to improve TFT accuracy.

Rinne test: does the tuning fork position affect the sound amplitude at the ear?

Background

Guidelines and text-book descriptions of the Rinne test advise orienting the tuning fork tines in parallel with the longitudinal axis of the external auditory canal (EAC), presumably to maximise the amplitude of the air conducted sound signal at the ear. Whether the orientation of the tuning fork tines affects the amplitude of the sound signal at the ear in clinical practice has not been previously reported. The present study had two goals: determine if (1) there is clinician variability in tuning fork placement when presenting the air-conduction stimulus during the Rinne test; (2) the orientation of the tuning fork tines, parallel versus perpendicular to the EAC, affects the sound amplitude at the ear.

Methods

To assess the variability in performing the Rinne test, the Canadian Society of Otolaryngology – Head and Neck Surgery members were surveyed. The amplitudes of the sound delivered to the tympanic membrane with the activated tuning fork tines held in parallel, and perpendicular to, the longitudinal axis of the EAC were measured using a Knowles Electronics Mannequin for Acoustic Research (KEMAR) with the microphone of a sound level meter inserted in the pinna insert.

Results

47.4 and 44.8 % of 116 survey responders reported placing the fork parallel and perpendicular to the EAC respectively. The sound intensity (sound-pressure level) recorded at the tympanic membrane with the 512 Hz tuning fork tines in parallel with as opposed to perpendicular to the EAC was louder by 2.5 dB (95 % CI: 1.35, 3.65 dB; p < 0.0001) for the fundamental frequency (512 Hz), and by 4.94 dB (95 % CI: 3.10, 6.78 dB; p < 0.0001) and 3.70 dB (95 % CI: 1.62, 5.78 dB; p = .001) for the two harmonic (non-fundamental) frequencies (1 and 3.15 kHz), respectively. The 256 Hz tuning fork in parallel with the EAC as opposed to perpendicular to was louder by 0.83 dB (95 % CI: −0.26, 1.93 dB; p = 0.14) for the fundamental frequency (256 Hz), and by 4.28 dB (95 % CI: 2.65, 5.90 dB; p < 0.001) and 1.93 dB (95 % CI: 0.26, 3.61 dB; p = .02) for the two harmonic frequencies (500 and 4 kHz) respectively.

Conclusions

Clinicians vary in their orientation of the tuning fork tines in relation to the EAC when performing the Rinne test. Placement of the tuning fork tines in parallel as opposed to perpendicular to the EAC results in a higher sound amplitude at the level of the tympanic membrane.

The Otologist’s Tuning Fork Examination—Are You Striking It Correctly?

Objective

To determine if the manner in which a tuning fork is activated affects its vibrational response.

Study Design

Diagnostic test assessment.

Setting

Hearing Center of Excellence laboratory.

Subjects and Methods

A Polytec OFV-5000 scanning vibrometer was used to measure the vibrational response of 256-Hz, 512-Hz, and 1024-Hz tuning forks after activation. The tuning forks were activated to varying intensities by striking 4 unique surfaces: the head, palm, a metal surface, and a wood table.

Results

The fundamental frequency of the individual tuning fork was the dominant observed frequency in all testing scenarios. Additional nonharmonic frequencies were noted when the 256-Hz and 512-Hz tuning forks were struck off metal and wooden surfaces.

Conclusions

Additional nonfundamental sound frequencies produced secondary to striking a tuning fork off a metal object or a wooden table could affect clinical tuning fork examination and complicate decisions regarding surgical candidacy.