Keywords

1 Introduction

According to the 2023 report from the World Health Organization (WHO), approximately 5.3% of the world’s population, or around 466 million people, are hearing impaired. This is an increase on 2018 when the percentage was 5.2% (World Health Organization, 2023). A person with hearing impairment is defined as an individual experiencing a loss in auditory capabilities, resulting in an inability to receive or rely on the auditory input necessary for understanding speech (Hauser et al., 2006). The primary challenge faced by individuals with hearing impairments revolves around communication. Sign language is the fundamental mode of communication for individuals with hearing impairments. Factors such as the limited number of individuals proficient in sign language and the lack of support for sign language in many information sources adversely affect the communication between individuals with hearing impairments and those with normal hearing.

Individuals with hearing impairments or hearing difficulties encounter significant challenges and multifaceted problems in various aspects of their lives, ranging from communication to education, health, and social interaction (Iezzoni et al., 2004). For instance, in the field of education, challenges arise due to the absence of suitable technological tools and inadequate accessibility and usability features in learning platforms, leading to difficulties in accessing educational materials (Batanero-Ochaita et al., 2021). Another example of inequality is observed in the workplace, where individuals with hearing impairments face technical challenges, including impacts on job performance and safety, a range of issues related to diminished ability to hear warning signals, as well as social problems such as communication difficulties, social isolation, and challenges in interacting with colleagues (Morata et al., 2005).

In contemporary times, rapid technological advancements and the widespread dissemination of the information age have significantly expanded individuals’ access to information and communication opportunities. However, a group that may not fully benefit from these advancements is individuals with hearing impairments. Particularly, the increasing popularity of audio-based content and applications may pose barriers for individuals with hearing impairments in achieving equal access on these platforms. Tools such as voice assistants, podcasts, video conferences, and social media platforms enable us to exchange information, engage in entertainment, and foster social interactions within seconds. Nevertheless, these tools may create challenges for individuals with hearing impairments in accessing information. Accessibility is a concept of critical importance for individuals with hearing impairments in the digital age. The equitable, fair, and inclusive design of technological advancements plays a vital role in enhancing societal participation and equal opportunities for all individuals. To fully enable individuals with hearing impairments to benefit from this digital revolution, significant responsibilities lie with technology manufacturers and service providers. Therefore, accessibility is not merely a luxury but a necessity. While individuals with hearing impairments may not naturally acquire the ability to speak, solutions are being developed through technology and science to overcome these disadvantages (Schriempf, 2009). Assistive technologies play a crucial role in overcoming the communication challenges fundamentally faced by individuals with hearing impairments (Bishop et al., 2000; Gugenheimer et al., 2017). Many assistive technologies have been developed to address communication problems, especially for individuals with hearing impairments, through technology. Technologies that automatically generate subtitles for video content facilitate access for individuals with hearing impairments. Sign language translation applications expand the communication abilities of individuals with hearing impairments (San-Segundo et al., 2012), and specially designed hearing aids and applications assist them in being more active in their social and professional lives (Stark & Hickson, 2004).

The increasing importance and frequent research on assistive technologies for the hearing impaired makes it both necessary and important to present the current trends and outlook of this field. Therefore, it will be determined in which direction the studies in this rapidly changing field have evolved, which aspects should be emphasized, and new horizons will be opened for researchers working in this field. In this context, this study, which performs bibliometric mapping of research on assistive technologies for the hearing impaired, is important in terms of defining the field in detail and drawing a general picture. Bibliometric analysis aims to examine the evolution of published literature on a topic. The term bibliometrics is defined as the application of statistical and mathematical methods to texts. Bibliometrics has emerged as an important research area in various branches of science. Bibliometrics offers the possibility to study the productivity of any literature in detail (Mukherjee et al., 2022).

This chapter examines assistive technologies for communication difficulties that facilitate the communication of hearing-impaired individuals with normal hearing, provide access to various information sources, and improve their daily lives. Assistive technologies are classified under three main headings: sound enhancement and transmission technologies, communication and access technologies, and finally warning and notification technologies. In addition to this review, bibliometric analysis methods will be used to analyze the development, use, and impact of these technologies in detail. This analysis will play a critical role in identifying research trends, important studies, and future research directions in the field.

1.1 Sound Enhancement and Transmission Technologies

These assistive technologies can be divided into two categories: hearing aids and frequency modulation (FM) systems. Hearing aids are electronic devices primarily consisting of a microphone, amplifier, and speaker that capture and amplify external sounds, transmitting them to individuals with hearing loss. They come in analog and digital types, with digital variants converting sound into digital signals, offering improved sound quality and customization options (Zeng et al., 2008). FM systems, on the other hand, transmit the voice of a specific speaker directly to hearing aids, incorporating a microphone and receiver. By reducing background noise and echoes, these systems enhance the clarity of following the speaker (Lewis, 1994). While hearing aids capture and amplify sounds from the surrounding environment, transmitting them to the ears of individuals with hearing loss, FM systems transmit the sound from a specific source (usually a teacher) directly to the hearing aid, reducing background noise and ensuring clearer sound transmission (Pittman et al., 1999).

1.2 Communication and Access Technologies

Expanding on the section about communication and access technologies for individuals with hearing or speech impairments, recent literature provides a deeper insight into the advancements and critical analysis of assistive technologies (AT), brain–computer interfaces (BCIs), mobile applications, and among others. These technologies play a significant role in enhancing communication, accessibility, and overall quality of life for individuals with hearing or speech impairments.

Assistive Technologies (AT): Shanmugam and Marimuthu (2021) provide a critical analysis and review of AT, highlighting its significant impact on improving the quality of life for dysarthric patients by overcoming communication difficulties. The study emphasizes the importance of AT in the rehabilitation of individuals with speech disorders, including design considerations and the impact of technology.

Brain–Computer Interfaces (BCIs): BCIs offer potential improvements in communication for people unable to use traditional augmentative and alternative communication devices. Brumberg et al. (2018) discuss the current state of BCI, focusing on its application in AAC, its efficacy, and the future of BCI as an addition to AAC access strategies. This tutorial aims to provide AAC specialists with foundational knowledge for clinical application of BCI.

Hearing Aid Technologies: Advances in hearing aid technology have allowed for a more efficient, cost-effective hearing assistive system. Das (2021) reviews the advancements in hearing aid technology, emphasizing the potential of IoT for developing an effective hearing assistant device. This highlights the shift toward innovative solutions that improve the functionality and accessibility of hearing aids for individuals with hearing impairments.

Teletypewriter (TTY) or Telecommunication Device for the Deaf (TDD): TTY/TDD devices are equipment designed for individuals with hearing or speech impairments. They include a keyboard and display or printer, allowing written communication over the telephone line and connection to TTY/TDD compatible services. This technology has increased individuals’ independence in telephone communication, but it has started to be replaced by internet-based communication platforms and more advanced technologies in contemporary times (Maiorana-Basas & Pagliaro, 2014).

Video Relay Service (VRS): Video Relay Service (VRS) enables individuals with hearing or speech impairments to conduct telephone conversations using sign language through a video device and an interpreter. This service facilitates more natural and fluent communication with other individuals (Saladin & Hansmann, 2008).

Captioning Systems: These technologies transform sounds and visuals into text and find application in various areas such as TV programs, movies, online videos, live matches, and conferences. Captioning systems, especially, make different types of videos more accessible for individuals with hearing impairments (Alsalamah, 2020).

Sign Language Translation Systems: Sign language is the primary mode of communication for individuals with hearing impairments. These technologies can work in two ways. The first method involves technological solutions that translate written or spoken text into sign language. These systems use computer-generated avatars or animations to represent information in sign language movements, thus facilitating access to information for individuals with hearing impairments (Sanaullah et al., 2022). The second method involves technological tools that detect sign language movements, converting them into text or spoken language, or translating written text into sign language. This helps individuals with hearing impairments communicate more effectively (Wadhawan & Kumar, 2021).

Mobile Applications: Mobile applications enhance the lives of individuals with hearing impairments by facilitating communication, access to information, and active participation in society (Alnfiai & Sampali, 2017). Mobile applications offer solutions tailored to the specific needs of individuals with hearing impairments, such as providing real-time transcripts for classes and meetings, finding accessible job listings, and granting access to entertainment content suitable for the hearing impaired.

1.3 Alert and Notification Technologies

Vibrating Alert Devices: Devices employing vibrations to notify individuals with hearing impairments of significant sounds or events contribute to enhancing their safety, independence, and overall well-being in daily life (Harkins et al., 2010).

Alerting Lights: Alerting lights are devices that use flashing lights to inform individuals with hearing impairments of important sounds or events. Alerting lights and vibration systems are often used together to draw attention to significant sounds and events for individuals with hearing impairments. While alerting lights provide visual feedback, vibration systems offer tactile feedback, each presenting different advantages and disadvantages based on the individual’s needs and preferences.

The presence of individuals with hearing impairments worldwide and the opportunities provided by technology to improve their quality of life support not only individual success but also societal integration. As discussed in the first section, the challenges faced by individuals with hearing impairments hold a significant place in the general structure of society and technological advancements. In the second section, we will assess the impact, usage, and effectiveness of these technological developments on individuals with hearing impairments. Analyzing general trends and patterns in the scientific literature through recent innovations in access to information and communication, we will comprehensively examine the scope and impact of existing and potential assistive technologies for individuals with hearing impairments. This approach will unveil the practical applications and real-world impact of these technologies on the lives of individuals with hearing impairments.

2 Method

This chapter provides a comprehensive review of research trends in assistive technologies for the hearing impaired through of bibliometric analysis. It first describes the methodology used for the bibliometric analysis. It then provides a comprehensive assessment of the results, shedding light on key patterns and emerging themes in the literature on assistive technologies for the hearing impaired.

In this study, a bibliometric research design was employed to analyze articles related to the use of assistive technology in individuals with hearing impairments. As part of the bibliometric methodology used in this study, various aspects were examined, including the number of publications, authors, subject areas, and the inclusion of specific keywords in articles related to the research topic (Donthu et al., 2021).

Bibliometric analysis plays a crucial role as a statistical method in mapping the existing knowledge situation in a specific field, determining new research areas, and extracting critical data for various purposes, including supporting current scientific findings (Ayaz et al., 2021; José de Oliveira et al., 2019). The primary data source for this study was the Scopus database, recognized for its comprehensive coverage of multiple databases. The following query was executed to obtain data:

$$\begin{array}{*{20}c} {\left( {{\text{deaf}}*{\text{OR}}\;{\text{``}}{\rm{hard}}\;{\text{of}}\;{\rm{hearing}}{\text{''}}\;{\text{OR}}\;{\text{``}}{\rm{hearing-impaired}}} \right.\;{\text{OR}}} \\ {\left. {\text{``}}{{\rm{unhearing}}{\text{''}}\;{\text{OR}}\;{\text{``}}{\rm{unable}}\;{\text{to}}\;{\rm{hear}}{\text{''}}} \right)\;{\text{AND}}\;\left( {\text{``}}{{\rm{assistive}}\;{\rm{technologies}}{\text{''}}\;{\text{OR}}} \right.} \\ {\left. {\left( {{\text{assistive}}\;{\text{AND}}\;{\text{techno}}*} \right)\;{\text{OR}}\;\left( {{\text{digital}}*{\text{AND}}\left( {{\text{tool}}\;{\text{OR}}\;{\text{tech}}*} \right)} \right)} \right)} \\ \end{array}$$

Publications were selected to be included in this study based on predefined inclusion and exclusion criteria. Inclusion criteria encompassed articles discussing the use of assistive technologies for individuals with hearing impairments, published in scientific journals indexed in Scopus, and containing relevant keywords. Exclusion criteria covered publications with limited access (e.g., lacking full-text access), available only in abstract form, or not relevant to the research topic.

Various bibliometric software tools, such as Word Cloud Analysis, Trend Topics, TreeMap, and Clustering by Coupling, were utilized for visualization and analysis. Additionally, a descriptive analysis covering publication counts, authors, subjects, and keyword usage was performed on bibliometric data. The bibliometric study aimed to categorize and identify publications related to the use of assistive technologies in individuals with hearing impairments based on their topics, publication years, and authors. A co-citation network analysis was conducted to reveal relationships among publications related to the research topic.

2.1 Research Questions

  1. 1.

    How has the development of publications on the use of assistive technology in individuals with hearing impairments progressed in recent years?

  2. 2.

    What types of documents are frequently published regarding the use of assistive technology in individuals with hearing impairments?

  3. 3.

    Which countries demonstrate the highest level of activity in research on the use of assistive technology for individuals with hearing impairments in education?

  4. 4.

    In publications related to the use of assistive technology in individuals with hearing impairments, which language is predominantly used?

  5. 5.

    What specific research areas are commonly investigated in the context of the use of assistive technology for individuals with hearing impairments?

  6. 6.

    Which organizations are most actively involved in research on the use of assistive technology for individuals with hearing impairments?

  7. 7.

    Which authors are prolific in publishing research on the use of assistive technology for individuals with hearing impairments?

  8. 8.

    What are the most frequently cited documents in global research on the use of assistive technology for individuals with hearing impairments?

  9. 9.

    Which keywords are most commonly found in research on the use of assistive technology in individuals with hearing impairments?

  10. 10.

    How are publications on the use of assistive technology in individuals with hearing impairments visually distributed in a TreeMap format?

3 Findings

3.1 Number of Publications on the Use of Assistive Technology in Individuals with Hearing Impairments Over the Years

A total of 1294 studies were identified, and data were collected through comprehensive searches. The data presented in Fig. 1 demonstrate a substantial volume of publications on this topic over the years. From 1970 to 2012, the number of publications remained relatively stable with minor fluctuations. Particularly noteworthy is a significant increase in the number of publications between 2014 and 2019. A noticeable upward trend has been observed since 2014, reaching the highest number of publications in 2022 with a total of 120 publications. As of October 2023, the number of publications has been identified as 88. This analysis indicates a growing body of research in this field, highlighting the increasing significance of the topic in the scientific literature.

Fig. 1
A graph of articles versus the years. The line starts at around 0 and then follow an upward trend as the year increases.

Annual publication numbers

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3.2 Number of Publications on the Use of Assistive Technology in Individuals with Hearing Impairments by Document Type

Figure 2 illustrates the distribution of publications categorized by document type in the utilized database. The analyzed documents encompass various types, including articles, conference papers, reviews, book chapters, conference reviews, books, notes, short surveys, data papers, and errata. The data reveals 588 articles, 485 conference papers, 81 reviews, 61 book chapters, 61 conference reviews, 8 books, 6 notes, 2 short surveys, 2 data papers, and 1 erratum. While articles are the most prevalent document type, errata are the least common. The diversity of document types in this dataset underscores the variety of research approaches employed in examining the subject matter.

Fig. 2
A bar graph of number of articles versus the document types. Article has the highest number of 588, followed by conference paper of 485, and then the lowest number is 6, 2, and 1 for note, short survey, and retracted.

Number of articles by document types

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3.3 Number of Publications on the Use of Assistive Technology in Individuals with Hearing Impairments by Country

Upon examining the Fig. 3, it is observed that contributions to publications on the use of assistive technology in individuals with hearing impairments have been made from a total of 86 countries. The United States leads in publication frequency with 345 publications, followed by India with 101 publications, Brazil with 88 publications, the United Kingdom with 76 publications, and Germany with 57 publications. The diversity of authors from various countries highlights global interest and participation in the field of assistive technology use for individuals with hearing impairments.

Fig. 3
A bar graph of number of articles versus the countries. The United States of America has the highest number, whereas Japan and China have the lowest number of articles.

Number of articles by country

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3.4 Investigation of Publications on the Use of Assistive Technology by Hearing-Impaired Individuals According to Languages

Figure 4 presents data on the distribution of publications related to the use of assistive technology by hearing-impaired individuals, categorized by the languages in which they were written. The dataset comprises 16 languages, with a total of 1220 publications, and English has the highest number of publications. Following English, there are 28 publications in Portuguese, 10 in Spanish, 8 in German, 6 in French, 4 in Russian, 3 in Korean, and 2 each in Turkish, Swedish, Chinese, and Japanese. Additionally, there is one publication each in Slovenian, Italian, Hungarian, Danish, and Czech.

Fig. 4
A bar graph of number of publications versus the language types. English has the highest number of publications of 1220, whereas the Danish and Hungarian have the lowest numbers.

Number of publications by language types

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These data emphasize that English is the dominant language in research on the use of assistive technology by hearing-impaired individuals. However, it is important to note that research in other languages plays a significant role in achieving a more comprehensive understanding and addressing a more diverse audience.

3.5 Number of Publications on the Use of Assistive Technology by Hearing-Impaired Individuals According to Research Areas

The information in Fig. 5 categorizes the number of publications on the use of assistive technology by hearing-impaired individuals according to research areas. These areas encompass a wide range of fields, including Computer Science, Engineering, Medicine, Social Sciences, Health Professions, Mathematics, Arts and Humanities, Physics and Astronomy, Psychology, Biochemistry, Genetics and Molecular Biology, Decision Sciences, Material Science, Business, Management and Accounting, Neuroscience, Environmental Science, Nursing, Chemical Engineering, Energy, Chemistry, Multidisciplinary, Agriculture and Biological Sciences, Economics, Econometrics and Finance, Pharmacology, Toxicology and Pharmacy, Earth and Planetary Sciences, Immunology and Microbiology, and Dentistry.

Fig. 5
A bar graph of number of publications versus the categories. Computer science has the highest number, whereas energy and chemistry have lowest number of publications.

Number of publications by research areas

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Among these areas, Computer Science research stands out with 574 publications, followed by Engineering with 325 publications and Medicine with 303 publications. On the other hand, Dentistry Research is the least represented among all scientific fields, with only one article.

3.6 Number of Publications on the Use of Assistive Technology by Hearing-Impaired Individuals According to Institutions

The dataset includes a total of 160 institutions, and their contributions to publications on the use of assistive technology by hearing-impaired individuals are illustrated in Fig. 6. The City University of New York (USA) leads in this field with 21 publications, followed by the Rochester Institute of Technology (USA) with 15 publications and Gallaudet University (USA) with 14 publications. Other significant institutions such as Instituto Superior de Engenharia do Porto (Portugal), Universidade de São Paulo (Brazil), and the University of Montreal (Canada) also have a noteworthy number of publications. These findings provide insights into the distribution of research conducted by various institutions on the use of assistive technology by hearing-impaired individuals.

Fig. 6
A bar graph of number of publications versus the institutions. City University of New York has the highest number, whereas University of Pittsburgh has the lowest number of publications.

Number of publications by institutions

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3.7 Number of Publications on the Use of Assistive Technology by Hearing-Impaired Individuals According to Authors

A total of 159 authors have been identified in the dataset. Figure 7 categorizes the number of publications on the use of assistive technology by hearing-impaired individuals based on the contributing authors. There are 9 authors with the highest number of publications, each having contributed between 6 and 13 publications. Particularly noteworthy are authors with the most publications: H. Levitt with 11 publications, P. Escudeiro and W. Wittich with 10 publications each, and N. Cercone and S. Nanayakkara with seven publications each. These data provide a general overview of authors who have made significant contributions to research in the field of assistive technology use by hearing-impaired individuals.

Fig. 7
A bar graph of number of publications by author. Levitt H has the highest number of publications, whereas Prietch and Aschendorff have the lowest number.

Number of publications by author

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3.8 Most Global Cited Documents

Figure 8 illustrates the top 10 most cited documents worldwide. The first article, written in 2012 and titled “Clinical Practice Guideline,” was published in Otolaryngology–Head and Neck Surgery. This document has accumulated a total of 756 citations with an average of 63.00 citations per year. Additionally, its Normalized TC value is 19.09. The article discusses the interaction of technology with health-related assistive technologies and how it can shape guidance and applications in this field. Focusing on cases where patients present symptoms of sudden hearing loss (SHL), the study emphasizes how the accurate diagnosis and effective management of these symptoms can be enhanced through technology. In particular, this study encourages the use of advanced technologies in the diagnosis and management of sudden-onset hearing losses.

Fig. 8
A graph of cited publications versus the values. STACHLER R J has the highest number, whereas LEE B G has the lowest number.

Most global cited publications

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In 2006, the Trends in Amplification journal published an article titled “Effects of Age on Auditory and Cognitive Processing: Implications for Hearing Aid Fitting and Audiologic Rehabilitation.” This article has received 300 citations, with an annual citation rate of 16.67 and a Normalized TC value of 13.18. The text explores questions triggered by age-related auditory and cognitive differences, highlighting developments led by research in these areas. The advancements discussed underscore the necessity of using technology to better understand auditory processing and the auditory needs of aging individuals. This is crucial in the design and functionality of hearing aids, headphones, and other auditory assistive devices. The text also mentions “intelligent” hearing aids and emphasizes advances in digital signal processing in auditory devices, reflecting the need to use technology to enhance the functionality and efficiency of hearing aids for aging individuals.

Additionally, in 2008, the Journal of Rehabilitation Research & Development published an article under the title “Cochlear implants: Current designs and future possibilities.” This document has received 242 citations, with an average annual citation rate of 15.13 and a Normalized TC value of 12.17. The article introduces cochlear implant technology as an advanced neural prosthesis for individuals with hearing loss, focusing on its development and effectiveness. The text indicates that cochlear implants are the most successful among neural prosthetics in restoring function. It provides information on how the design and performance of cochlear implants have been developed and improved, demonstrating the continuous evolution of technology to assist more people. The text emphasizes the current status and limitations of cochlear implant technology and highlights the potential for future improvements. This underscores the ongoing need for the continuous development of assistive technologies for individuals with hearing loss.

Finally, other prominent articles address the role and future development of assistive technologies in areas such as hearing loss, hearing devices, communication technologies, and language policies. Assistive technologies play a crucial role in improving the quality of life for individuals with hearing loss and facilitating their communication.

3.9 Keyword Analysis

Word clouds are a useful tool for visualizing the frequency of keywords in bibliometric data. They provide a quick and easy way to grasp the main themes of research topics. By analyzing the data presented in Fig. 9, we can create a Word Cloud that visually represents the most frequently encountered keywords in research related to “the use of assistive technology by individuals with hearing impairment.”

Fig. 9
A word cloud illustrates the following words. Sign. Hearing aid. Accessibility. Implant. Cochlear.

Word Cloud

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In this research, the most prominent keywords include “sign language,” “hearing aid,” “cochlear implant,” “accessibility,” “speech perception,” and “gesture cognition.“ Additionally, “machine learning,” “deep learning,” “e-learning,” “augmented reality,” and “human–computer interaction” are other noteworthy keywords seen with significant frequency. On the other hand, some keywords such as “blind,” “children,” “haptics,” “libras,” “deafblind,” and “deaf people” are observed with lower frequency. Despite being less common, these keywords remain relevant to research on this topic.

3.10 TreeMap

A TreeMap is a data visualization tool that represents data hierarchies using rectangles. The size of these rectangles reflects the frequency or quantity of the data; larger rectangles indicate more significant data amounts. By analyzing the dataset presented in Fig. 10, we can create a TreeMap visually representing the most frequently occurring terms in research articles.

Fig. 10
A tree map contains the following data. Assistive technology 211. Hearing aid 90. Sign language 80. Technology 13. Children 11. Speech recognition 14.

TreeMap

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The most frequently used keywords in the articles provide a general overview of topics related to individuals with hearing impairment. These encompass various technologies, terms, and subjects used to improve the lives of individuals with hearing impairment, facilitate their communication, and help them cope with hearing loss. Among the crucial topics aimed at enhancing the integration of individuals with hearing impairment into society and improving their quality of life are as follows:

Assistive Technologies for Hearing-Impaired Individuals: Technologies supporting individuals with hearing impairment aim to reduce hearing loss, enhance auditory abilities, and facilitate communication. The term “Assistive technology” includes various devices that individuals with hearing impairment can use in their daily lives and communications. “Hearing aid” is a common technological solution used to improve the auditory abilities of individuals experiencing hearing loss. “Cochlear implant” refers to a specialized implant system used to provide hearing abilities to individuals with hearing loss. Additionally, “Assistive listening devices” include technological devices that help individuals with hearing impairment communicate better, aiming to improve their lives and promote societal inclusion.

Sign Language and Communication: Sign language plays a critical role in effective communication for individuals with hearing impairment, enabling them to communicate with each other and individuals with auditory abilities. “Sign language recognition” technologies assist in recognizing and understanding sign language, facilitating better communication for individuals with hearing impairment. Various communication tools and skills are also employed to strengthen communication for individuals with hearing impairment, promoting their empowerment and increased integration into society.

Technology and Progress: In the context of technology and progress, approaches such as “Deep learning” and “Machine learning” are essential for developing technologies that support individuals with hearing impairment. These artificial intelligence approaches aim to make assistive technologies more effective, facilitate communication, and enhance the quality of life for individuals with hearing impairment. Progress in deep learning and machine learning represents advancements in developing technologies that offer increased access and opportunities for individuals with hearing impairment, allowing them to communicate more effectively, receive education, and better integrate into society.

Education and Learning: Technologies used to support education and learning for individuals with hearing impairment are crucial. Terms such as “E-learning” and “Education” refer to educational technologies and processes aimed at providing accessible and customizable learning opportunities for individuals with hearing impairment. Online education offers accessible and personalized learning opportunities, designed to meet individual needs and support communication. These technologies assist individuals with hearing impairment in continuing their education, enhancing their careers, and promoting their societal inclusion.

Accessibility and Inclusion: Concepts of “Accessibility” and “Inclusion” aim to make the lives of individuals with hearing impairment more inclusive and accessible. “Accessibility” refers to facilitating easier access for individuals with hearing impairment in physical, digital, and social environments, enabling them to access public buildings, online resources, and communication tools easily. “Inclusion” encourages equal rights for individuals with hearing impairment in all areas of society, including education, employment, culture, and social activities. Inclusion supports individuals with hearing impairment in living richer and more effective lives and celebrates the diversity of their communities. The concepts of accessibility and inclusion underscore the importance of studies and developments aiming to provide individuals with hearing impairment with increased access and opportunities.

These keywords reflect the technologies and related terms used to improve the lives, communication, and education of individuals with hearing impairment. Additionally, these keywords emphasize the significance of studies and advancements aiming to provide individuals with hearing impairment with increased access and opportunities.

4 Discussion and Conclusion

The outcomes of the bibliometric analysis on the adoption of assistive technology by individuals with hearing impairments provide a comprehensive depiction of the field’s evolution over time. Notably, the pronounced surge in scholarly publications between 2014 and 2019 highlights an escalating interest in and acknowledgment of the pivotal role assistive technologies plays in ameliorating the life quality of the hearing impaired. This observation is in alignment with the findings reported by Valencia-Arias et al. (2022), corroborating the significance of these technologies. Such a trend not only mirrors advancements in technology but also indicates an increasing consciousness and commitment toward fostering inclusivity and accessibility within society.

The diversity in document types, with articles being the most common and errata the rarest, highlights robust scholarly engagement across a range of platforms, including peer-reviewed journals and conference proceedings. This variety indicates that the exploration of assistive technology for individuals with hearing impairments is advancing not only through theoretical frameworks but also through practical implementations and critical evaluations of existing technologies. Moreover, the international dispersion of publications, prominently featuring contributions from the United States, India, Brazil, the United Kingdom, and Germany, accentuates the global pertinence and applicability of assistive technologies, effectively transcending geographical and cultural boundaries. This scenario aligns with the observations made by Valencia-Arias et al. (2022), underscoring compatibility with their findings. Additionally, there is a noticeable trend of increased publication output from India, indicating a growing emphasis on contributing to this field of research within the region.

The linguistic analysis revealing English as the dominant language in this research area points toward the need for increased multilingual research dissemination. While English serves as a global academic lingua franca, the presence of publications in 16 different languages signifies the global interest and the necessity to cater to non-English speaking populations. This inclusivity could further enhance the understanding and application of assistive technologies worldwide.

The analysis of the most cited documents and keywords provides valuable insights into the research community’s focus areas. The emphasis on clinical guidelines, auditory and cognitive processing, and cochlear implant technology underscores the critical intersections between technology, healthcare, and rehabilitation. Moreover, the frequent mention of keywords related to sign language, hearing aids, cochlear implants, and machine learning illustrates the dynamic nature of the field, incorporating both traditional and cutting-edge technologies.

In conclusion, the bibliometric analysis reveals a vibrant and rapidly evolving research landscape, marked by a significant increase in publications, a diverse array of document types, global participation, and a multidisciplinary approach. This growth indicates the field’s critical importance and the ongoing need to explore, innovate, and improve assistive technologies for the hearing impaired. Future research should continue to build on this foundation, focusing on inclusivity, technological advancements, and the practical application of findings to ensure that assistive technologies become more accessible, effective, and tailored to the needs of individuals with hearing impairments. The trajectory of this research area promises further advancements and broader implications for enhancing the quality of life and communication for those with hearing impairments, offering a roadmap for researchers, practitioners, and policymakers alike. As this analysis does not assess the quality of the publications reviewed, the results provide only a quantitative perspective and therefore do not include a qualitative assessment.