Department of Hearing and Speech Sciences, Faculty of Allied Health Sciences, Health Sciences Center, Kuwait University, Kuwait
Received date: November 16, 2015 Accepted date: February 11, 2016 Published date: February 18, 2016
Citation:Al-Meqbel A (2016) A Pilot Study of the Relationship between Autism Spectrum Disorder and Hearing Loss. Commun Disord Deaf Stud Hearing Aids 4:152. doi: 10.4172/2375-4427.1000152
Copyright: © 2016 Al-Meqbel A. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Visit for more related articles at Journal of Communication Disorders, Deaf Studies & Hearing Aids
Objective: To determine the occurrence of peripheral hearing loss and autism spectrum disorder in children enrolled in special education schools. Methods: Twenty-two children diagnosed with ASD, confirmed by developmental medicine, were recruited from a special ASD school. Each participant underwent audiological testing: transient otoacoustic emission and impedance audiometry were used. Results: The 22 participants were all boys, aged from 7 to 15 years, with mean ± 10.63 years and SD 2.4 years. TOAE was present in both ears in five ASD children, but it was absent in one or both ears in the remaining 17 participants. Seventeen of the 22 participants had type B and C tympanogram and an absence of TOAEs. Conclusion: Children with ASD are at risk of peripheral hearing loss, due to middle ear problems. A complete audiological evaluation is recommended in all cases where ASD is suspected, so as not to delay diagnosis of hearing impairment in the event that hearing loss and ASD co-exist. Objective assessment measurements should be used to assess the auditory system in ASD children.
Conductive hearing loss; Autism spectrum disorder; Middle ear; Tympanometry; Transient otoacoustic emission
ASD: Autism Spectrum Disorder; TOAE: Transient Otoacoustic Emission
Autism spectrum disorder (ASD) constitutes a group of developmental disorders characterized by impairments in social interaction and communication, and by restricted, repetitive, and stereotyped patterns of behaviors . Typical signs of autism include, but are not limited to, speech and language delay, regression of developmental millstones at 18-24 months of age, avoidance of eye contact, tactile defensiveness, and engagement in repetitive and selfstimulating behaviors .
Approximately 4% of children who are hard of hearing have cooccurring ASD [3-6]. Audiologists may be among the earliest healthcare professionals encountered by a child with an ASD diagnosis and his or her family. Consequently, it is important that audiologists are aware of ASD and the symptoms that may be associated with the disorders. Increased awareness of the signs of ASD may help to facilitate earlier identification and intervention for children for better communication. Audiologists who work clinically with children may see a child with an ASD prior to a formal diagnosis of the disorder. It is common for a child with an ASD to have been suspected of having a hearing loss before the diagnosis of ASD was made.
Early identification of both disorders is extremely important to ease the effects of the dual diagnosis, since the co-morbidity of hearing loss and ASD may considerably complicate language development and communication skills. Because both hearing deficits alone and ASD alone could contribute to communication and social delays, identification of the true dual diagnosis is challenging [7,8].
Behavioral hearing assessments in ASD children are particularly challenging as a result of the difficulty in making contact with them. Using objective hearing methods, therefore, would seem to be the most suitable approach to assess hearing function in school-aged children with behavioral problems such as ASD .
One such method is transient otoacoustic emissions (TOAEs) testing. TOAEs can be easily recorded in children. They provide valuable information regarding the active process of the cochlea and outer hair cell integrity in individuals with clinically normal hearing and possible structural abnormalities that cannot be detected with behavioral testing.
Another objective method that can be used as an objective testing of auditory system is tympanometry, which evaluates the middle ear status. ASD children are less able to provide a reliable response when using a behavioral method. Therefore, it is vitally important that sensitive and specific physiologic measurement be available to provide information about functioning of the middle ear .
Twenty-two children diagnosed with ASD, confirmed by developmental medicine, were recruited from a special school. The gender and age of each child were recorded, and otoscopic examination ruled out pathology of the external auditory canal and middle ear, which can influence results. Each child underwent two types of audiological testing: TOAE test and tympanometric assessment. The data were analysed using basic statistical tests. TOAE responses were measured using OToRead system Interacoustics, Denmark, and middle ear status was evaluated using MADSEN OTOflex 100-tympanometer, Otometrics.
The 22 children diagnosed with ASD enrolled in the special school were all boys. Their ages ranged from 7 to 15 years with mean ± 10.63 and SD 2.4. The tests consisted of TOAE bilaterally and impedance audiometry examination. TOAE was present in both ears in five ASD participants; in the remaining 17 participants it was present in just one ear or in neither ear. Tympanometric curves associated with a healthy middle ear on both sides (namely A) were described in seven ASD children. Tympanometric curves associated with dysfunctional middle ear (namely B and C curves) on both or one side were described in the remaining 15 children (Table 1).
Table 1: Characteristic of ASD children.
We studied the occurrence of hearing loss in ASD children with different levels of intellectual functioning, using a combination of TOAEs and impedance audiometry testing. TOAE examination is widely used as a tool for screening in hearing loss. Seventeen out of the 22 ASD children tested had an absence TOAEs. The absence of otoacoustic emission is considered to be typical of conductive hearing loss in the course of otitis mediawith effusion[11,12]. The impedance audiometry examination is most commonly used as an objective examination allowing the assessment of middle ear functions.
The presence of types B and C tympanometric curves is most frequently observed in chronic otitis media with effusion, which is a common cause of conductive hearing loss in children .
Children with ASD have an increased prevalence of series otitis media and associated temporary conductive hearing loss . Teachers and family are often unable to recognize the presence of middle ear problems such as Otitis media and eustachian tube dysfunction.
Complete audiological assessment is recommended in all cases where ASD is suspected or confirmed, so as not to delay the diagnosis of hearing loss in the event that hearing loss and ASD co-exist.
Children with ASD are at risk of peripheral hearing loss due to middle ear problems. A complete audiological assessment is recommended, therefore, in all cases where ASD is suspected or confirmed, so as not to delay the diagnosis of hearing impairment in the event that hearing loss and ASD co-exist. Objective measurement such as TOAE and tympanometry should be used to assess the hearing condition in ASD children.