November 2015 - January 2016: Use of OAEs in Telehealth (Teleaudiology) Applications


About the guest Editors:  


Dr. Mark Krumm is an associate professor in the School of Speech Pathology and Audiology at Kent State University in Kent, Ohio (USA).  He has been involved with telehealth applications for over a decade and has published a number of papers describing audiology telehealth use with pure tone audiometry, otoacoustic emissions, immittance, video-otoscopy and the auditory brainstem response (ABR). Dr. Krumm has also chaired the American Speech Language and Hearing Association (ASHA) committee on Telepractice as well as the first American Academy of Audiology (AAA) task force on Telehealth.


Vidya Ramkumar is a faculty member at the Department of Speech, Language and Hearing Sciences at Sri Ramachandra University, Chennai, India. She is also a PhD candidate in Audiology at, Sri Ramachandra University,  in the area of tele-audiological application in newborn hearing screening in rural villages. She worked in the area of tele-audiological applications in testing hearing among school children as a part of her Fulbright-Nehru Doctoral Professional Research fellowship, which she completed in 2014. She was co-investigator of project titled “Newborn hearing screening using tele-audiology” and received funding from the Indian Council of Medical Research, Government of India. She has also been involved in development of mobile phone based applications in hearing screening and tinnitus. She has published articles in the area of tele-audiology, tinnitus and community based hearing screening programs. 


An Update: Use of OAEs in Telehealth (Teleaudiology) Applications

By Mark Krumm, Ph.D and  Vidya Ramkumar, M.S.



Telehealth is the provision of services by practitioners from their location (the distant site) to clients located at site in another location (the local site). Audiologists have been using telehealth (tele-audiology) services in one form or another since the 1990s. There were obvious benefits to using otoacoustic emissions and telehealth including supporting newborn hearing screening and diagnostics programs (see Figure 1).



Figure 1. DPOAEs and TEOAEs could be used with telehealth technology to create better hearing healthcare for all individuals including infants


           The first known attempt to use otoacoustic emissions for telehealth purposes can be traced to proof of concept trials by Virtual Corporation in the mid-1990s. This work formed the basis of a master’s thesis produced by Schmiedge (1997). In his thesis, Schmiedge described a comprehensive study employing the Virtual Corporation system and PC Anywhere software to obtain DPOAEs remotely. While most of the thesis was dedicated to assessing the reliability of remote computing of DPOAEs over a local area network (LAN), Schmiedge also conducted remote computing trials with subjects located in another country (Canada) using a telephone modem.

           Schmiedge’s thesis was interesting for a number of different reasons. First, his thesis demonstrated that remote computing technology using DPOAEs was practical in the mid-1990s. He also found that DPOAEs could be reliably obtained using different mediums of telecommunications technology including a telephone modem. This study also implied that telehealth could be utilized with relative ease using off the shelf software and computerized audiology test systems as suggested in Figure 2.


Figure 2. Remote computing components indicated by Schmiedge (1997). This model would work either over a network or by modem connection.


                    Schmiedge’s interest in the use of DPOAEs for this thesis stemmed from the objective nature of otoacoustic emissions. Specifically, one could evaluate remote computing technology using DPOAEs without the bias of the subjects. In addition, DPOAEs are conducted rapidly and provide significant diagnostic information to determine hearing status. A further advantage to the use of DPOAEs (or TEOAEs) is these recordings provide a measurement of the noise floor in the ear canal. Consequently, clinicians could use this information to determine if the level of background noise at the client test  site was appropriate for testing.

                   Yet another compelling reason for Schmiedge was the ever-growing evidence that TEOAEs and DPOAEs would take a central role in universal newborn hearing screening and diagnostic programs. To be successful, these programs would have to be provided to newborns living in underserved areas. Hence audiologists would be required to work in distant communities or infants (and their parents) would have to travel significant distances to metropolitan centers for hearing health care services. A probable outcome was that travel would create barriers and infants would be lost to follow-up services. O’Neal et al. (2000), addressing the subject of service discontinuity, suggested that new paradigms must be developed to ensure that each infant is connected to needed services regardless of circumstances .One such paradigm was audiology services provided via telehealth. As webcam quality and speeds increasing by leaps and bounds, it became possible to see clear images of the client and OAE results on a computer screen early in the last decade (see Figure 3)


                         Figure 3. Telehealth screen capture of infant testing via telehealth in 2003


                 There were other obvious advantages to using telehealth to supplement universal newborn hearing programs. Health care personnel involved with newborn hearing services in rural locations would need consistent training, oversight and feedback by audiologists in order to provide quality services. Telehealth technology could be used to provide that oversight via video conferencing. Further, if necessary, the practitioner could actually control testing of otoacoustic emissions directly using remote computing technology if a computerized OAE system was available at the client (local) site.

                 Citing the benefits of telehealth, Krumm and Schmiedge (2005) wrote a paper discussing the implications of telehealth to support EDHI services. Synchronous applications were described by these authors as a method in which the clinician could test a client over a network or modem in real time. Krumm and Schmiedge also suggested that synchronous applications could include interactive video, remote computing software and computerized auditory brainstem response (ABR) or OAE systems for remote computing applications (see Figure 4). Asynchronous (or "store and forward") telehealth procedures were also described. Asynchronous telehealth methods are employed when client data is printed out, scanned in a computer (or faxed) and sent to a clinician for interpretation. Such data may include immittance results, hearing aid analyzer or real ear results, case history information, video otoscopy images, and video clips of the client being tested. An asynchronous system is diagramed in Figure 5.


Figure 4. A schematic of remote computing hardware, software and personnel  needed for remote computing testing. Remote computing software and interactive video are used at both sites. Audiology hardware is only located at the community test site.



                                Figure 5. An asynchronous method of sending DPOAEs to clinicians  involved with EDHI services.


               Additionally, a hybrid model was described in which a combination of synchronous and asynchronous technology is utilized for the provision of audiology telehealth services (Krumm 2007; Swanepoel and Hall, 2010).  For example, audiologists using a hybrid model might wish to use interactive video and remote DPOAEs testing procedures (which is synchronous technology). These results could be supplemented through asynchronous technology with local site assistants sending clinicians scanned files of information such as immittance, prior ABR/OAE results or video otoscopy records. Used in this way, hybrid telehealth systems appear to offer the most flexibility for practitioners wishing to provide a full array of hearing health care services. In other words, the hybrid model invites an “anything that works” mindset that results in the use of both synchronous and asynchronous audiology systems for hearing assessment. Figure 6 offers how both synchronous and asynchronous results might be transmitted to a clinician from the infant test site.


                      Figure 6. A hybrid system utilizing diagnostic tests for EDHI services.


              The first published study in which telehealth technology was used to assess infant hearing was described by Krumm, Huffman, Dick and Klich (2008). In this study, the investigators used distortion DPOAEs and automated ABR (AABR) to provide follow-up screenings to infants who had failed their initial hospital hearing screening at birth. Approximately 30 newborns, ranging 11-45 days of age, were rescreened using face-to-face measurements and by telehealth technology. The results of this study indicated that no significant differences existed between the use of telehealth and face-to-face measurements when infants were rescreened for DPOAEs and screening ABR. As this was a proof of concept study, further investigations or needed to examine "real world" applications.

                 The next telehealth study incorporating the use of hearing measures with young children was conducted by Ciccia et al. in 2010. This study was unique in that it was conducted with preschool children attending an inner-city medical center in Cleveland, Ohio (USA) for hearing healthcare services. While most telehealth projects are conducted in rural areas, it should be recognized that individuals who live in inner-city communities also have significant barriers to hearing healthcare. These barriers include professional shortages, accessibility of clinical locations to families and socio-economic issues (Ciccia et al., 2010).

                  In the study by Ciccia et al, the investigators provided preschool aged children with hearing screening services including otoscopy, pure tone testing, DPOAEs, tympanometry and otoscopy. As most of the children were under 6 years of age, children were generally screened using play audiometry and/or with DPOAEs. This project length was two years and over 411 children were screened during this time.

                   During the first year, the hearing screening was conducted by an audiologist supervising a trained assistant via interactive video. The audiologist trained the assistant in conducting otoscopy, immittance testing, screening DPOAEs and in play audiometry for preschool children. The assistant was a student in a local undergraduate speech-language and hearing program.  The “video only” model in year one was adopted to address the immediate need to provide hearing screenings at the screening site. During the second year, all of the hearing screening was done synchronously by remote computing technology using webcams, a video otoscope, a computerized audiometer and remote computing software, a computerized tympanometer and distortion product otoacoustic emissions systems. The results of the first year of telehealth screening results were compared to the second year results. Interestingly, virtually no difference existed between the two vastly different telehealth protocols of year one and year two.

                   The results of this study are notable for a couple of reasons. The first is that a relatively simple telehealth model was employed for hearing screening in the first year of the study. This telehealth model required a supervising audiologist (using interactive video from the distant location) to oversee screening procedures of an assistant at the screening site. In contrast, during the second year, the audiologist actually conducted the hearing testing using synchronous (and remote) computing technology. This study suggests that while remote computing is a reasonable and desirable method for audiologist employ in telehealth, the use of interactive video may be used to effectively supervise well trained assistants\s to do preschool hearing screenings (including possibly play audiometry). In addition, the parents of the children screened in the study indicated they favored telehealth technology and thought this technology was equally as good as those services provided face-to-face. This outcome may be due to the fact that telehealth services were provided as a community based service in which clients and their parents felt comfortable. Consequently, this project offers valuable information about using more than one telehealth model to provide hearing screening services for preschool children.

                    An EDHI telehealth study described in two papers by Ramkumar et al. were published in 2013 and in 2014. In this study, many infants in rural India were tested with remote computing technology through satellite and DSL connections. A mobile van equipped with satellite technology for telemedicine applications was utilized at the infant test site in rural Indian villages (see Figure 7).  Additionally, local DSL services were located by project personnel finding hotspots in the local community where DSL services were available. As bandwidth for connectivity was restricted, the remote computing technology at the infant site required a dedicated interactive video line to one laptop and a separate line to a laptop dedicated for remote computing services.


Figure 7. The telemedicine van stationed in the rural community (top centre), health  worker cleaning a neonates skin for ABR (bottom left), Tele-ABR conducted inside the mobile tele-van (bottom right) 

               Further, the researchers trained community health workers employed in rural villages to act as facilitators for EDHI diagnostic services. These village health care workers were trained in depth in providing necessary services at the local site including equipment troubleshooting, OAE probe placement and ABR electrode placement. The village health care workers were local and trusted individuals that parents often knew in their communities (Rajendran et al. 2014). Consequently, there was little doubt these facilitators were important for establishing rapport with local community members who agree to have their newborns tested via telehealth (see Figure 8).

                                 Figure 8. Village health worker screening a neonate in the rural community in India.

                 One of the obstacles in this study was obtaining the desired bandwidth to provide telehealth services in rural India. In spite of technology issues associated with slower satellite mediated Internet and land based DSL speeds, these researchers were eventually able to provide EDHI diagnostic services to over 100 infants using remote computing technology (Ramkumar et al., 2014). Comparison of outcomes between tele and face to face ABR on neonates demonstrated no significant difference even in spite of tremendous connectivity barriers (Ramkumar et al., 2013).

          In a study that paralleled the work of Ramkumar et al. (2013), Hayes et al.  (2015) described comprehensive infant hearing services which were provided from clinicians located in the USA  to infants located in Guam utilizing mostly remote computing technology. Specifically, Hayes et al. were able to conduct complete EDHI evaluations using DPOAEs, ASSR, ABR, video otoscopy and tympanometry. These evaluations were made possible through trained EDHI assistants located in Guam who were responsible to prepare newborns for hearing testing. Various videos of teleaudiology sessions with children can be seen at the National Center for Hearing Assessment and Management, Utah State University at the following link:.

                 Hayes et al. detailed significant programmatic needs such as training of assistants, considerations for parent satisfaction, clinician satisfaction and troubleshooting hardware issues. Of particular interest, this paper documented the need to test telehealth equipment (including both diagnostic and interactive video equipment) to ensure quality services to the local site in Guam. Noted in this study were issues relating to poor audio associated with the interactive video equipment and occasional loss of connectivity with the Internet. To overcome the poor audio issues associated with interactive video, a telephone was used to provide communication between the USA and Guam sites (Hayes et al., 2012). They also found the disconnection of the Internet was not disruptive even when occurring during a test session.

                     Finally, it is apparent that Hayes et al. (2015) spent a great deal of effort to provide in-depth training of facilitators at the client site in Guam. In addition to this systematic training, audiologists from Colorado were sent to Guam for a week of in-service training with Guam EDHI personnel and to inspect the local telehealth site facilities for suitability of service provision.

                     An important comment in the article by Hayes et al., (2015) concerns the cost and sustainability of audiology and telehealth services. Specifically these researchers indicated the startup cost for the telehealth services were substantial with equipment costs exceeding $60,000. Also, as this project was supported by a federal grant, the infants evaluated in this project were not charged a fee for service. Hayes et al. (2015) indicated sustainability of the project would require continued forms of income. This comment is of interest as virtually all audiology telehealth projects which have been described in the literature are either proof of concept or grant funded projects. These projects often end because no further source of funding is available. A notable exception appears to be projects which are supported by the federal government funding. Clearly, innovative entrepreneurship funding strategies may be needed to sustain teleaudiology programs.



OAE assessment has a long history with telehealth applications. Virtually all work in telehealth is with EDHI applications.  Clearly, OAEs can be used effectively and reliably with telehealth technology in both synchronous and asynchronous methods with essentially the same outcomes. But researchers indicate that telehealth assistants must have substantive training when supporting audiologists at client test sites. In addition, internet connectivity and audio communication may be problematic in telehealth services. However, prototyping telehealth equipment should lead to identification of these issues.

Data is lacking concerning the provision of EDHI services for children and behavioral testing. Visual reinforcement audiometry (VRA) appears difficult to do under a telehealth paradigm due to complex equipment needs. However, play audiometry appears reasonable with proper assistant training.

Finally, telehealth has limitations and clinicians must determine boundaries when clients should be seen in person. Such circumstances might include (but are not limited to) clients who are hard to test, second opinions, pediatric ear mold impressions, pediatric hearing aid fittings or parental concern over telehealth technology.  On the other hand, it is clear that telehealth offers the capability for providing services to individuals in underserved locations even when the clinician is literally a continent away.




Ciccia, A,Whitford, B, Krumm, M, McNeal, K. (2011).  Improving the access of young urban children to speech, language and hearing screening via telehealth.  J Telemed Telecare, 17,(5), 240-244.


Hayes, D., Eclavea, E., Dreith, S., & Habte, B. (2012). From Colorado to Guam: infant diagnostic audiological evaluations by telepractice. The Volta Review, 112(3), 243–253.

Hayes, D., Boada, K. and Coe, S. (2015). Early hearing detection and intervention by telepractice. SIG 18 Perspectives on Telepractice, 5, 38-47. 

Krumm, M. (2007). Audiology telemedicine. Journal of Telemedicine and Telecare,13(5) 224-229.

Krumm M, Huffman T, Dick K, Klich R. Telemedicine for audiology screening of infants. J Telemed Telecare 2008;14:102–4.

Krumm, M., Ribera, J., and Schmiedge, J., (2005).Using a telehealth medium for objective hearing testing: Implications for supporting rural universal newborn hearing screening programs (UNHS).  Seminars In Hearing.  26 (1), 3-12.

O’Neal J, Finitzo T, Littman T. Neonatal hearing screening: follow-up and diagnosis. In: Roeser, Valente, Hosford-Dunn, eds. Audiology Diagnosis. New York: Thieme; 2000:530.

Rajendran, A., Ramkumar, V. & Nagarajan, R., 2014. Perception of “mothers of beneficiaries” regarding a rural community based hearing screening service. International Journal of Pediatric Otorhinolaryngology, 78(12), pp.2083–2088

Ramkumar, V., Hall, J. W., Nagarajan, R., Shankarnarayan, C. V., & Kumaravelu, S. (2013). Tele-ABR using a satellite connection in a mobile van for newborn hearing testing. Journal of Telemedicine and Telecare, 19, 233–237.

Ramkumar, V., Nagarajan, R., Kumaravelu, & Hall, J.W.  (2014). Providing tele ABR in rural India. SIG 18 Perspectives on Telepractice, March 2014, 4,:30-36.

Swanepoel, D., & Hall, J. (2010). A Systematic review of telehealth applications in audiology. Telemedicine & E-Health, 16(2), 181–200.