Transient evoked otoacoustic emissions testing for screening of sensorineural deafness in puppies

<p><b>Background:</b> Transient evoked otoacoustic emissions (TEOAE) are widely used for human neonatal deafness screening, but have not been reported for clinical use in dogs.</p> <p><b>Hypothesis/Objectives:</b> To investigate the feasibility of TEOAE testing in conscious puppies and the ability of TEOAE testing to correctly identify deaf and hearing ears, as defined by brainstem auditory evoked response (BAER).</p> <p><b>Animals:</b> Forty puppies from 10 litters.</p> <p><b>Methods:</b> Prospective study on puppies presented for hearing assessment as part of a congenital deafness BAER screening program. Hearing status was determined using BAER. TEOAE testing was performed after the BAER assessment and the results of the TEOAE testing were compared with the hearing status for each ear. Parameters were tested for normality using the D'Agostino Pearson test and comparisons between the deaf and hearing ears were made using Mann-Whitney tests.</p> <p><b>Results:</b> TEOAE testing was readily performed in puppies presented for congenital deafness screening. Using analysis parameters based on those used in human neonatal hearing screening, TEOAE testing correctly identified all deaf ears, as defined by BAER testing, with a sensitivity of 100% (95% CI: 56-100%) for diagnosing deafness and specificity of 78% (95% CI: 66-87%).</p> <p><b>Conclusions and Clinical Importance:</b> TEOAE testing is an effective screening modality for identifying congenital sensorineural deafness in dogs. In light of the simpler and less expensive equipment, TEOAE testing has the potential to improve access to hearing screening and through this reduce the prevalence of congenital deafness in the dog.</p&gt

DPOAEs in Children With Sickle Cell Disease

The purpose of this study was to investigate distortion product otoacoustic emissions (DPOAEs) in young normal-hearing children with sickle cell disease (SCD). It was hypothesized that the prevalence of DPOAEs and response amplitudes would be lower than those in children with normal hemoglobin due to suspected compromised cochlear function as a result of vaso-occlusive events characteristic of SCD. Twenty African-American children with SCD and 15 African-American children with normal hemoglobin participated. Distortion product OAEs were evoked by thirteen primary tone pairs with f2 frequencies ranging from 1000 to 4500 Hz. The primary tones were presented at and L1 and L2 levels of 70 and 60 dB SPL (high) and 50 and 40 dB SPL (low), respectively. The findings of this study were completely unexpected and contrary to our original hypotheses. The likelihood of detecting a DPOAE response was not related to the clinical status of the children. Distortion product OAE amplitudes were significantly larger for children with SCD (p = .01). Educational Objectives: After completing this article the reader will (1) have a basic knowledge of the audiometric complications of sickle cell disease and (2) appreciate the differences in DPOAEs between young normal-hearing children with sickle cell DPOAEs in Children With Sickle Cell Disease 3 disease and young normal-hearing children with normal hemoglobin

Insights Into Elevated Distortion Product Otoacoustic Emissions In Sickle Cell Disease: Comparisons of Hydroxyurea-treated and Non-treated Young Children

Distortion product otoacoustic emissions (DPOAEs) were examined in 15 normal- hearing African-American children between the ages of 6 and 14 years with homozygous sickle cell disease (SCD), who were on a regimen of hydroxyurea (HDU), a drug that reduces inflammatory processes and symptoms of SCD; a matched group of 15 African- American children with homozygous SCD not on HDU; and 15 African-American children with normal hemoglobin. DPOAEs were evoked by 13 primary tone pairs with f2 frequencies ranging from 1000 to 4500 Hz. Increased DPOAE amplitudes, believed to be a precursor of eventual hearing loss, were evident in children with SCD who were not receiving HDU. Those taking HDU had DPOAE amplitudes similar to normal controls. These findings suggest that HDU, in addition to reducing symptoms of SCD, may play a role in inhibiting or preventing cochlear pathology and hearing loss in individuals with SCD. Key Words: distortion product otoacoustic emissions; sickle cell disease; hydroxyurea Abbreviations: ABR = auditory brainstem response; DPOAE = distortion product otoacoustic emission; HDU = hydroxyurea; HbSS = homozygous sickle cell disease; ICAM = intercellular adhesion molecule; M = mean; OAE = otoacoustic emission; p = probability; PECAM = platelet-endothelial cell adhesion molecule SCD = sickle cell disease; SD = standard deviation of the mean; SOAE = spontaneous otoacoustic emission; TEOAE = transient evoked otoacoustic emission; VCAM = vascular cell adhesion molecule

Musical Ratios in Sounds from the Human Cochlea

The physiological roots of music perception are a matter of long-lasting debate. Recently light on this problem has been shed by the study of otoacoustic emissions (OAEs), which are weak sounds generated by the inner ear following acoustic stimulation and, sometimes, even spontaneously. In the present study, a high-resolution time–frequency method called matching pursuit was applied to the OAEs recorded from the ears of 45 normal volunteers so that the component frequencies, amplitudes, latencies, and time-spans could be accurately determined. The method allowed us to find that, for each ear, the OAEs consisted of characteristic frequency patterns that we call resonant modes. Here we demonstrate that, on average, the frequency ratios of the resonant modes from all the cochleas studied possessed small integer ratios. The ratios are the same as those found by Pythagoras as being most musically pleasant and which form the basis of the Just tuning system. The statistical significance of the results was verified against a random distribution of ratios. As an explanatory model, there are attractive features in a recent theory that represents the cochlea as a surface acoustic wave resonator; in this situation the spacing between the rows of hearing receptors can create resonant cavities of defined lengths. By adjusting the geometry and the lengths of the resonant cavities, it is possible to generate the preferred frequency ratios we have found here. We conclude that musical perception might be related to specific geometrical and physiological properties of the cochlea