Wideband reflectance in Down syndrome.

OBJECTIVE: Children with Down syndrome (DS) have a high incidence of middle ear disorders and congenital abnormalities of the external, middle and inner ear. Energy reflectance (ER), a wideband acoustic immittance (WAI) measurement parameter, can measure the sound energy reflected or absorbed in the ear canal over a wider range of frequencies more efficiently and faster than conventional single-tone 226 Hz tympanometry. The aim of the present study was to compare the WAI measurements of children with DS with those of typically developing, normal-hearing children according to their tympanometric findings. METHODS: Four groups of children with Down syndrome (age range: 2 years and 4 months to 16 years and 3 months; mean age: 8.5 yr) with normal tympanograms (19 ears), flat tympanograms (13 ears), mild negative pressure tympanograms (6 ears between -100 and -199 daPa at the admittance peak) and severe negative pressure tympanograms (4 ears at -200 daPa or lower at the admittance peak) were assessed. All findings were compared with data obtained from 21 ears of a healthy control group (age range: 3 years and 1 month to 13 years and 11 months; mean age: 7.9 yr). The subjects underwent tympanometry with a 226-Hz probe tone frequency and ER measurements along the 200-6,000 Hz range with a chirp stimulus using the Middle-Ear Power Analyzer (MEPA3 - HearID) by Mimosa Acoustics (Champaign, IL), software, version 3.3 [38]. RESULTS: Statistically significant differences were observed in the ER curves for some comparisons between the studied groups. There was also a negative correlation between the static acoustic admittance at the tympanic membrane level and ER measured with a chirp stimulus at 500 and 1,000 Hz. The discriminant analysis technique, which used a chirp stimulus at 1,000 and 1,600 Hz to classify the participants' data based on ER values, achieved a correct classification rate of 59.52% for participants with DS. CONCLUSION: While groups with abnormal middle ear status, as indicated by tympanometry, showed higher ER values compared to the DS tymp A group and the control group, similar reflectance curves were observed between control group and the DS tymp A group. WAI shows promise as a clinical diagnostic tool in investigating the impact of middle ear disorders in DS group. However, further research is required to investigate this issue in narrower age range group and a larger sample size.

Wideband reflectance in newborns with present transient-evoked otoacoustic emissions.

PURPOSE: To characterize the normal values of acoustic energy reflectance obtained with pure-tone stimulation in neonates prior to hospital discharge. METHODS: Seventy-seven infants (37 girls and 40 boys) were evaluated by measuring acoustic reflectance using pure-tone stimuli, transient-evoked otoacoustic emissions, and tympanometric probe frequencies of 226 Hz and 1 kHz. RESULTS: At low frequencies (258-750 Hz), greater energy reflectance was observed, while at medium frequencies (1-3 kHz), greater energy absorption was observed. There was no difference between ears or between genders. CONCLUSION: Normal energy reflectance values were obtained for the studied population. The data indicate a reflectance curve with a distinct configuration for the studied age.

Reflectância de banda larga em recém-nascidos com presença de emissões otoacústicas evocadas por transiente / Wideband reflectance in newborns with present transient-evoked otoacoustic emissions

OBJETIVO: Caracterizar os valores normais de reflectância da energia acústica obtidos com estímulo de tom puro na população neonatal antes da alta hospitalar. MÉTODOS: Setenta e sete recém-nascidos (37 meninas e 40 meninos) foram avaliados por meio das medidas de reflectância acústica, utilizando estímulos de tom puro, emissões otoacústicas por transientes e timpanometria com sondas de frequências de 226 Hz e 1 kHz. RESULTADOS: Nas baixas frequências (258 a 750 Hz) foi observado um valor elevado de reflectância da energia, enquanto nas médias frequências (1 a 3 kHz) obteve-se uma maior absorção da energia. Não existiu diferença entre orelhas e entre gêneros. CONCLUSÃO: Foram caracterizados os valores normais de reflectância da energia para a população estudada. Tais dados revelaram uma curva de reflectância com configuração peculiar para a idade.

PURPOSE: To characterize the normal values of acoustic energy reflectance obtained with pure-tone stimulation in neonates prior to hospital discharge. METHODS: Seventy-seven infants (37 girls and 40 boys) were evaluated by measuring acoustic reflectance using pure-tone stimuli, transient-evoked otoacoustic emissions, and tympanometric probe frequencies of 226 Hz and 1 kHz. RESULTS: At low frequencies (258-750 Hz), greater energy reflectance was observed, while at medium frequencies (1-3 kHz), greater energy absorption was observed. There was no difference between ears or between genders. CONCLUSION: Normal energy reflectance values were obtained for the studied population. The data indicate a reflectance curve with a distinct configuration for the studied age.