Telehealth aims to provide health care services to underserved populations across the world using communication and information technology. The word telehealth means health care at a distance [1]. Advanced technology and connectivity have helped in bridging the gap between patients and health care providers, thereby overcoming economic and geographical barriers. It has also enabled better access to professional training resources and mentoring for the health care professionals. Teleaudiology can be applied either in a synchronous, asynchronous or hybrid model. A synchronous model allows for real-time delivery and monitoring of services via videoconference. An asynchronous model uses the store-and-forward methodology, where the test results are stored and reviewed later. The hybrid model uses both synchronous and asynchronous models [2].

The American Academy of Audiology [3] and American Speech-Language-Hearing Association [4] have propagated and supported the use of telehealth services through position statements. These services are especially applicable for those patients with limited access to healthcare resources, cost-efficient and can act as a supplement to face-to-face services [5]. Telehealth can be applied directly to patient care as well as indirectly for training health professionals [1]. Likewise, teleaudiology has found applications in hearing screening, diagnosis, intervention, and providing training/education to professionals [6,7].

In the global scenario, there is a lack of educated, trained, and employed health workers for the number of people in need of medical services [8]. Audiological services help to provide early hearing detection, diagnosis, and intervention for individuals with hearing loss. A lack of adequate hearing health professionals has been noted in both developed and developing countries [6]. Thus, the application of teleaudiology helps in providing the audiological services along with an added advantage of serving the under-served and enhancing follow-up services.

A systematic review of telehealth applications in audiology shed light on sparse information available on patient and clinician perception regarding acceptance and use of telehealth applications. It further emphasized that teleaudiology holds a significant promise in helping to extend audiological services and the need to carry out empirical research [7]. Bush, et al. [9] reviewed the feasibility of implementing remote telehealth for providing auditory rehabilitation for users of hearing aids and cochlear implants. A paucity of literature was noted on cost-effectiveness, infrastructure, and reimbursement for longterm sustainability of these services. Another recent systematic review included 103 papers of which 32.1% focused on hearing [10]. Further, the majority focused on assessment (36.9%) and intervention (36.9%). The majority were published in the United States of America (32%) and followed by Australia (29.1%). Most studies concluded that telehealth has an advantage over face-to-face services. The review highlighted the need among audiologists to adapt to telehealth applications. These professionals should be familiar and aware about the use of telehealth for diagnostic and therapeutic purposes as well as for professional development activities [10].

With the advances in telecommunications, Internet services, and satellite communication it is now possible to focus on further development and advancement of the teleaudiology services. This can especially be beneficial in countries with poor service seeker to provider ratio. This expansion of services can be made possible with a thorough understanding of attitudes and perceptions of audiologists towards teleaudiology. Thus, the present systematic review aimed at exploring the existing literature on attitudes and perceptions of audiologists towards the teleaudiology. Further, it intended to ascertain the sources of their existing knowledge, and barriers to the successful uptake of teleaudiology.

The present systematic review was carried out using the Preferred Reporting Items for Systematic Reviews and Metaanalyses statement (PRISMA) guidelines [11]. It provides an evidence-based minimum set of items to conduct and report systematic reviews and meta-analyses.

A total of 250 hits were obtained across the four electronic databases, of which 45 were duplicates and were eliminated. Titles of 205 studies were screened of which 199 studies were excluded, as they did not suit the inclusion criteria. Only studies exploring opinions or knowledge towards teleaudiology and its application among audiologists were included. Studies on patient perceptions towards teleaudiology and use of teleaudiology in telehealth were excluded. Abstracts of six studies were screened from which four studies were found suitable. The back references of the included four studies were screened to identify any additional studies and one study was found to be suitable for inclusion. Thus, five studies were included for data extraction. Fig. 1 depicts the PRISMA flow chart for the study search and retrieval process for included studies. Table 1 displays the study characteristics such as study design, location, population, and questionnaire characteristics. Table 2 displays key data on experience and attitudes towards teleaudiology extracted from the five articles. Table 3 displays the methodological quality appraisal for the included studies.

Telehealth services have been available since the late 19th century with the first published evidence emerging around 20th century where electrocardiography data was transmitted across telephone wires [16]. The recent growth in the application of telehealth can be attributed to growing internet use. Telehealth has made possible applications both within and across national borders [17]. In terms of application in audiology, studies have been carried out to report its application in domains of hearing screening, diagnosis, intervention and continuing education programs. The use of internet has become part and parcel of day to day life which can be evidenced by the increase in access to the internet from 16% of the world population in 2005 to 47% in 2016 [18]. The use of internet and technology has made provision of medical and rehabilitative services available even in rural and remote areas where there is a lack of access to care. These advancements in technology can be noted even in the field of teleaudiology with, within and across country applications. This widespread use of teleaudiology has enabled providing precise and reliable results, thereby further increasing its application [6,7,19-21].

The present study provides a systematic review of studies on knowledge and perceptions of teleaudiology application among audiologists. It further helps to identify the knowledge sources as well as barriers to the application of teleaudiology as reported by the audiologists themselves. Five studies were shortlisted after systematically reviewing the literature available. Three of these studies were carried out on audiologists from USA, one from Canada, and one across the world. Across all the studies, a total of 1,747 audiologists were surveyed on their knowledge and perception of teleaudiology application.

The provision of teleaudiology depends on several factors such as service providers/audiologists, infrastructure, highspeed internet, cost and socio-cultural issues. The success of service delivery of such program lies to a great extent on the service providers and their role. Further, in recent years there has been an added impetus towards increasing the applicability of teleaudiology. Therefore, in this context, it becomes crucial to have an understanding of the existing knowledge and perceptions of audiologists towards teleaudiology. The review findings have been discussed in terms of sources and means to increase knowledge, perceptions towards the application of teleaudiology, barriers to uptake of application of teleaudiology.

The review sheds light on the existing knowledge and perceptions of teleaudiology applications among audiologists. Overall, positive attitudes was observed among audiologists towards applications of teleaudiology. The review also helped to identify the sources of knowledge gaps in the implementation of teleaudiology services. This will help in improving existing teleaudiology services as well as assist in overcoming some of the challenges faced.