title: Wideband reflectance in Down syndrome.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: School of Medicine (FMUSP)- Department of Physical Therapy, Speech Therapy and Occupational Therapy, University of Sao Paulo, São Paulo, SP, Brazil. Electronic address: jordanagri@gmail.com.
authors.forename: Jordana Costa
authors.initials: JC
authors.lastname: Soares
authors.affiliation: School of Medicine (FMUSP)- Department of Physical Therapy, Speech Therapy and Occupational Therapy, University of Sao Paulo, São Paulo, SP, Brazil.
authors.forename: Juliana Granja
authors.initials: JG
authors.lastname: Urosas
authors.affiliation: School of Medicine (FMUSP)- Department of Physical Therapy, Speech Therapy and Occupational Therapy, University of Sao Paulo, São Paulo, SP, Brazil.
authors.forename: Karenina Santos
authors.initials: KS
authors.lastname: Calarga
authors.affiliation: School of Medicine (FMUSP)- Department of Physical Therapy, Speech Therapy and Occupational Therapy, University of Sao Paulo, São Paulo, SP, Brazil.
authors.forename: Tathiany Silva
authors.initials: TS
authors.lastname: Pichelli
authors.affiliation: School of Medicine (FMUSP)- Department of Physical Therapy, Speech Therapy and Occupational Therapy, University of Sao Paulo, São Paulo, SP, Brazil.
authors.forename: Suelly Cecília Olivan
authors.initials: SC
authors.lastname: Limongi
authors.affiliation: School of Audiology and Speech Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Navid
authors.initials: N
authors.lastname: Shahnaz
authors.affiliation: School of Medicine (FMUSP)- Department of Physical Therapy, Speech Therapy and Occupational Therapy, University of Sao Paulo, São Paulo, SP, Brazil.
authors.forename: Renata Mota Mamede
authors.initials: RM
authors.lastname: Carvallo
mesh_terms: D000158:Acoustic Impedance Tests / Q000379:methods; D000162:Acoustics; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004314:Down Syndrome / Q000150:complications / Q000503:physiopathology*; D004427:Ear Diseases / Q000209:etiology / Q000503:physiopathology*; D007758:Ear, Inner; D004432:Ear, Middle / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011312:Pressure; D013016:Sound; D014432:Tympanic Membrane / Q000503:physiopathology*
keywords: Down syndrome; Energy reflectance; Hearing tests; Middle ear; Wideband acoustic immittance; Wideband reflectance