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Introduction

Acoustics is the science of sound, encompassing its production, transmission, and reception. Sound is ever present in all environments and, as a discipline, has applications in the earth sciences, engineering and physical sciences, life sciences, health and human sciences, and the arts. As a sensory modality, sound and vibrations are used by both animals and machines to communicate and gather information about the conditions around them. This is particularly true in the marine environment, where sound travels more efficiently and over larger distances compared to light, which attenuates rapidly and often vanishes within a few hundred meters of the surface. This report specifically addresses ocean acoustics, but many of the topics and ideas can be thought of interchangeably with underwater acoustics in lakes, rivers, bays, etc.

Underwater sounds carry indicators of the state of the ocean, conveying both characteristics of their sources and their complex interactions with ocean boundaries, basic ocean physical properties (e.g., changes in temperature, salinity), and objects (e.g., fish aggregations, turbulent microstructure, clues to habitat health) within the ocean volume. Sound in the ocean is generated intentionally by natural sources (e.g., volcanoes, earthquakes, animals), by humans (e.g., active sonar, echo sounders), and as a by-product of human activity (e.g., shipping, recreation, construction). As a result, ocean acoustics is highly intertwined with the physical, biological, chemical, and geological aspects of the ocean that define the field of oceanography. Sound and acoustic technologies are a primary tool in marine commercial and recreational fisheries that play an increasingly critical role in global food security (FAO, 2022). Furthermore, sound is used to explore and exploit the mineral riches of the deep ocean, which has broad diplomatic and environmental implications. As evidence of the growing recognition of the importance of ocean acoustics, ocean sound was recently added to the list of essential ocean variables for the Global Ocean Observing System and is listed with both Physics/Climate and Biology/Ecosystems (GOOS, 2020).

The field of ocean acoustics was the first of five National Naval Responsibilities (NNRs) established on August 31, 1998 (ONR, 2000). The NNR initiative was developed with input from the National Academies of Sciences, Engineering, and Medicine (the National Academies) and other organizations to provide stability to disciplines that are otherwise not supported by other branches of DoD or other federal agencies (TRB, 2011). However, there has not been a recent assessment of the ability of ocean acoustics education and expertise to keep up with workforce demands, not only within the USN but across the federal government, industry, research, and academia, or with advancements of acoustic platforms, technology, and capabilities. The last report on the issue was led by Lackie of the Applied Physics Laboratory at the University of Washington in 1997; it is over 25 years old and focused solely on naval applications.

Beyond fundamental ocean science, the discipline of ocean acoustics is expansive and continuing to grow. Its expertise is vital for several economic, environmental, and national security applications. At the national level, the Interagency Working Group on Ocean Sound and Marine Life has been tasked with coordinating and facilitating activities related to ocean sound among federal agencies. Ocean acoustics, both active and passive, is also the basis for technologies critical to the development of the blue economy and sustainable use of the ocean (EOP, 2022a, 2023). This has been highlighted in the presidential memorandum directing the development of a national strategy to map, explore, and characterize the U.S. Exclusive Economic Zone (EOP, 2022b). Acoustics is also critical to ocean energy development, as demonstrated by the recent establishment of the Center for Marine Acoustics at the Bureau of Ocean Energy Management (BOEM). As our understanding of the ocean grows, and our exploitation of its resources change with the developing blue economy, effects are anticipated on the acoustic environment of some marine habitats, creating the necessity of addressing how to wisely use acoustics for ocean exploration and development.

INTERDISCIPLINARY CHALLENGES

The field of ocean acoustics is complex, stemming from the inherent interdisciplinarity, integrating knowledge and skills from mathematics, the natural sciences, and engineering. The expanding applications of ocean acoustics, relating to biology, ecology, oceanography, and conservation, to name a few, contribute to an increasing need for additional education and training opportunities to support a robust workforce. The increasing diversification of ocean acoustics applications is evident in how the ocean acoustics community identifies with multiple Acoustical Society of America (ASA) technical areas (see Figure 1-1, red legend text). Within ASA,¹ the community includes subsets of members from the following technical areas: physical acoustics, underwater acoustics (UW), animal bioacoustics, acoustical oceanography (AO), signal processing, and computational acoustics.

Figure 1-1 depicts the decreasing numbers of acoustics professionals in a majority of the ASA technical areas. This is likely due to a combination of several factors identified by the committee, from the survey, and during the information-gathering panels, including an aging workforce, stagnant growth of education and training programs, and weak recruitment and retention. This is not unique to ocean acoustics and supporting disciplines, as declining membership in the different ASA technical areas (Figure 1-1) is a common trend. Strikingly, AO is one of the few areas with a flat membership trend; however, this contrasts with the sharp decline observed in UW. Biomedical acoustics is the only subdiscipline that experienced growth over the past 15 years.

In the academic landscape, content in ocean acoustics, general acoustics, and supporting disciplines is included in the following formal degree departments: mechanical engineering, electrical engineering, computer engineering, civil engineering, computer science, biology, physics, aerospace engineering, oceanography, ocean engineering, geophysics, and marine science. Yet, none of these formal degree names explicitly convey knowledge or expertise specific to acoustics. Pennsylvania State University, University of New Hampshire (UNH), and University of Massachusetts Dartmouth are the only three U.S. higher education institutions offering programs with degrees or certificates at the graduate level that specifically convey acoustics expertise in the diploma or certificate title.² Without a single discipline focus at the majority of U.S. institutions, students face challenges both during their educational matriculation and upon graduation, such as

1. a lack of interaction and awareness of acoustics materials between different departments and programs that leads to low course enrollment and risk of cancelation;
2. graduates with an emphasis in acoustics from programs in one discipline (i.e., mechanical engineering) encounter the challenge of being hired in other colleges/programs within academia (i.e., oceanography); and
3. graduates with a degree in traditional programs do not convey acoustics knowledge to future employers, which results in a discipline with no true or visible identity, making it challenging to attract new students and retain graduates on a career path in ocean acoustics and supporting disciplines.

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¹ ASA is a professional society that attracts membership from academia, government, and industry.

² Pennsylvania State University has a graduate program in acoustics, and both UNH and University of Massachusetts–Dartmouth have a graduate certificate in acoustics.

DIVERSITY IN AUDIENCE

As a historically naval discipline (Hackerman et al., 1990; Lackie, 1997), ocean acoustics has expanded with several direct applications, supporting the mission of federal agencies and organizations, industries, and nongovernmental organizations. As the need for ocean acoustics knowledge has grown and application of its techniques expanded, so too has the diversity of employers, career paths, education requirements, and students. The main avenue for education and careers was tightly linked to national security needs and supported by USN grants (Hackerman et al., 1990; Lackie, 1997). Although this relationship is crucial and still thrives today, new education and training opportunities outside of graduate-level education are necessary to meet expanding current and future workforce needs from a much broader portfolio of federal and industry stakeholders. In addition, the rapid growth of acoustic technologies requires that members of the technical workforce regularly update skills through formal schooling and professional development opportunities, including innovative and flexible training programs.

In August 2022, the U.S. Office of Science and Technology Policy (OSTP) issued a requirement for the results of all research produced with taxpayer dollars to be made “immediately available to the American public” (EOP, 2022b). Beyond core expertise in ocean acoustics, expertise in data management and information technology is needed to make the vast amounts of acoustics data being acquired publicly available. Public access to data collected for a specific project or purpose will increase their value by supporting innovative science and research beyond their original purpose. Data collection is expensive and often requires both equipment and vessel time. Growing expertise in the infrastructure to support acoustic data dissemination and analysis will directly contribute to identifying patterns and trends in long-term ocean acoustics time series and educating the future workforce by supplying real-world data to classrooms and elevating the visibility of the value of ocean sound (Data Management subsection in Chapter 6).

STUDY TASK AND APPROACH

In 2022, ONR sponsored the National Academies to conduct a study that evaluated the state of ocean acoustics education and expertise, considering the large number of federal and international initiatives underway relating to the ocean environment. The study considered the state of ocean acoustics expertise across all areas of ocean science, including ecology, biology, oceanography, ocean engineering, and ocean energy. It was also charged to examine not only the future demand for ocean acousticians across all ocean disciplines but also the state of the field in embracing and incorporating new technologies related to observations, data archiving and accessibility, cooperative metadata resource hubs, machine learning (ML), and artificial intelligence (AI) applications. Box 1-1 presents the full Statement of Task.

The committee built upon reports and evaluations of different aspects of ocean acoustics research and education (COL, 2018; Hackerman et al., 1990; Lackie, 1997) to address the Statement of Task. In reviewing historical documents, the committee used their suggested actions or recommendations as a starting point for developing this report and its own recommendations (see Table 6-1) to address the support needed for ocean acoustics research and education and preparation and recruitment of a diverse workforce. Tables 1-1 and 1-2 provide a summary of the itemized actions and recommendations, categorical classification of the potential resolution (e.g., fiscal, infrastructure, outreach), the committee’s assessment of progress since the time of the original report, and its consensus on the current/future relevance of the actions or recommendations. As expected, these actions and recommendations were largely reflective of defense needs; however, the committee assessed current relevance across all sectors and applications related to ocean acoustics.

Next, the committee collected information on specific areas outlined in the Statement of Task. This included (1) a thorough review of the literature; (2) contracting a consultant to develop, distribute, and analyze an online questionnaire; (3) several public information-gathering panels; and (4) its own collective knowledge and experience.

Education and training opportunities in the field of ocean acoustics and supporting disciplines have been available at a highly specialized level over the past 3–4 decades, and the committee devoted much thought to the need to expand these opportunities (before graduate school specialization) for the next generation of students, researchers, employees, and the public seeking to learn about the value, applications, methodologies, and technology of ocean acoustics.

The online survey, Ocean Acoustics Education and Expertise, was developed in consultation with Social Policy Research Associates (SPRA) to collect feedback from a variety of higher education institutions and workforce areas on the existing capacity to support the field of ocean acoustics and anticipated future needs. The survey was designed to reach a broad audience within the ocean acoustics community and help the committee understand the current state of education, needs for expertise, anticipated demand in the next decade, and needs for additional training opportunities.

The committee used academic and industry groups to reach a diverse group of respondents. The survey was distributed to individuals within academia, industry, government, and professional societies involved in ocean acoustics and related fields. Committee members promoted the survey at professional meetings and workshops, including the spring 2023 ASA meeting and 2023 Global Ocean Science Education Workshop, and recruited through their own networks to reach as wide and as diverse an audience as possible. The survey reached 200 individuals, of whom 61.5 percent completed or partially completed it. After the results were cleaned and analyzed, 110 unique responses were used to inform SPRA’s survey report (see Appendix B).

The survey was tailored to the following response categories: academia, workforce (with distinctions between industry and federal employees), and professional societies. The 110 responses included 59 academic respondents, 48 total workforce respondents (19 industry and 29 federal government), and three professional society respondents.

The survey was divided into five subsections: Background; State of Acoustics Education; Mentorships, Internships, Apprenticeships, & Competencies; Recruitment Strategies; and Future of Acoustics. More detailed results and analysis are provided in Chapters 3, 4, 5, and 6.

The survey was designed to reach a large portion of the ocean acoustics community, but completion was voluntary. It also allowed respondents to skip questions if they did not have specific information (e.g., specific student enrollment numbers) available. The results provided valuable insights and reached a broader portion of the ocean acoustics community than the committee would have been able to reach through other information-gathering means. However, the results may not be entirely reflective of the ocean acoustics community or the state of higher education and training due to the voluntary nature of responses, limitations in institutional data accessible to some respondents, and length. The survey was designed to be completed in approximately 20 minutes or less.

The committee also held several information-gathering panels and targeted discussions with individuals from academia, industry, and government sectors. These were an opportunity to invite speakers to share their personal expertise and engage in question-and-answer sessions around topics relating to the Statement of Task. The topics included the following:

• Workforce (Government, Academia, and Industry)
• Early-Career and Recent Graduates
• Higher Education and Training
• Outreach
• STEM Education
• Naval Training Programs

The committee did not include a detailed analysis or review of international programs during its information-gathering process because it fell outside the scope of this report. However, many international organizations that conduct work related to ocean acoustics could provide additional opportunities for training programs or workshops not covered in this report. Some examples include the International Council for the Exploration of the Sea Working Group on Fisheries Acoustics, Science and Technology, International Quiet Ocean Experiment, or, related to defense, the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization and Centre for Maritime Research and Experimentation.

REPORT STRUCTURE

The report is organized to present the state of ocean acoustics education and expertise and anticipated needs related to the future workforce. Chapter 2 starts by providing a historical summary of ocean acoustics education; Chapter 3 offers an assessment of current education and training opportunities targeting acoustics, ocean acoustics, and supporting disciplines. Chapter 4 contains a compilation of the current and potential future workforce and employment landscape. Chapter 5 evaluates methods for increasing workforce diversity and provides examples of education and training strategies to attract students and retain professionals in the ocean acoustics career pipeline. Finally, Chapter 6 analyzes the gaps between education opportunities and workforce needs and presents the committee’s recommendations to support ocean acoustics research and education now and in the future.

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