During the 2024-25 academic year, the Northeastern University Archives and Special Collections (NUASC) scanned 24,608 pages of archival materials for both in-person and remote researchers. This output has allowed NUASC to serve more researchers and broaden access to these primary sources by uploading them into the Digital Repository Service (DRS).
A photo from the National Center of Afro-American Artists records
Work to put these reference scans into the DRS began in 2023 with a backlog of scans from NUASC’s remote reference program. Archives staff understood the research value of readily available scans and wanted to make them more accessible to anyone, regardless of institutional affiliation or research goals. Uploading these files into the DRS was a collaborative effort between Metadata and Digital Projects Supervisor Drew Facklam, Reference and Outreach Archivist Molly Brown, and Reference and Reproductions Archivist Grace Millet.
Once a workflow was developed to clean up and provide information about the files, collections were identified based on community and researcher needs, as well as the quantity of scans. As of June 2025, 14,226 pages of digitized materials have been ingested into the DRS. Reference scans have come from the:
Reference scans are completed at a lower resolution than scans used for publication, though they are still entirely legible and usable for research purposes. Another important difference between reference scans and other digitized materials in the DRS is the format of reference scans’ titles, which allow users a glimpse into the inner workings of archival organization.
The titles of these files contain the collection number, box number, folder number, and folder title.
With this knowledge, anyone viewing these files can discern where they are located within NUASC’s collections. This allows for easy reference if a researcher might need to request a higher-quality scan of a specific item.
To learn more about what is available in the Digital Repository Service from NUASC, you can search our digitized collections or reach out to us at archives@northeastern.edu. The public services team is looking forward to continuing this expansion of access to collections stewarded by NUASC!
Captions play a key role in making audio and video content accessible. They benefit not only deaf and hard-of-hearing users, but also second-language learners, researchers scanning interviews, and anyone viewing content in noisy environments.
At the Northeastern University Library, we manage a growing archive of media from lectures and events to oral histories. Manually creating captions for all of this content is not a scalable solution, and outsourcing the task to third party services can be expensive, time-consuming, and inconsistent. Motivated by this, we have been exploring AI-powered speech-to-text tools that could generate high-quality captions more efficiently and cost-effectively.
Figure 1: Example of an ideal transcription output
We started by testing Autosub, an open-source tool for generating subtitles. Even using a maintained fork (copies of the original project that add features, fix bugs, or adapt the code for different use cases), Autosub did not offer significant time savings, and it was eventually dropped.
In summer 2023, the team began using OpenAI’s Whisper, which immediately cut captioning time in half. However, it lacked key features like speaker diarization (the process of segmenting a speech signal based on the identity of the speakers), and it often stumbled on long stretches of music or background noise which would require extra cleanup and made the output harder to use at scale.
As the AI for Digital Collections co-op on the Digital Production Services (DPS) team, I was responsible for researching and testing Whisper forks that could be realistically adopted by our team. I tested model performance, wrote scripts to automate captioning, debugged issues, and prepared tools for long-term use within our infrastructure.
Phase 1: Evaluating Whisper Forks
We looked for a model that could:
Handle speaker diarization
Distinguish between speech and non-speech (music, applause, etc.)
Output standard subtitle formats (like VTT/SRT)
Be scriptable and actively maintained
We tested several forks, including WhisperX, Faster Whisper, Insanely Fast Whisper, and more. Many were either too fragile, missing key features, or poorly maintained. WhisperX stood out as the most well-rounded: it offered word-level timestamps, basic diarization, reasonable speed, and ongoing development support.
Phase 2: Performance Testing
Once we chose WhisperX, we compared its various models to OpenAI’s original Whisper models, including large-v1, v2, v3, large-v3-turbo, and turbo. We tested six videos, each with different lengths and levels of background noises, and compared the models based on Word Error Rate (WER) (how often the transcription differed from a “gold standard, or human-created or -edited transcript), and processing time (how long it took each model to generate captions).
WhisperX’s large-v3 model consistently performed well, balancing speed and accuracy even on noisy or complex audio. OpenAI’s turbo and large-v3-turbo delivered strong performance but lacked diarization features.
Phase 3: Timestamp Accuracy Evaluation
Next, we assessed how precisely each model aligned subtitles to the actual audio — crucial for usability. We compared outputs from the WhisperX large-v3 model and the OpenAI turbo and large-v3-turbo models.
We used a gold standard transcript with human-reviewed subtitles as our benchmark. For each model’s output, we measured:
Start Mean Absolute Error (MAE) — average timing difference between predicted and actual subtitle start times
End MAE — same as Start MAE, but for subtitle end times
Start % < o.5s — percentage of subtitles with start times less than 0.5 seconds off
End % < 0.5s — same for start % < 0.5s, for end times
Alignment rate — overall percentage of words correctly aligned in time
WhisperX’s large-v3 model outperformed all other models significantly. In most of our test videos, it showed:
Much lower MAE scores for both start and end timestamps
Higher percentages of accurately timed subtitles (within the 0.5-second range)
Better overall word alignment rates
In fact, in several test cases, WhisperX was nearly three times more accurate than the best-performing OpenAI Whisper models in terms of timing precision.
Figure 2: WhisperX output vs. gold-standard transcript in a high-WER case
In one particular case, one WER result for WhisperX large-v3 showed a surprisingly disappointing score of 94% errors. When I checked the difference log to investigate, it was that the model had transcribed background speech that was not present in the gold standard transcript. So, while it was technically penalized, WhisperX was actually picking up audio that the gold standard did not include. This highlighted both the model’s sensitivity and the limitations of relying solely on WER for evaluating accuracy.
Figure 2 shows exactly that. On the left, WhisperX (denoted “HYP”) transcribed everything it heard, while the gold standard transcript (denoted “REF”) cut off early and labeled the rest as background noise (shown on the right).
What’s Next: Integrating WhisperX
We have now deployed WhisperX’s large-v3 model to the library’s internal server. It’s actively being used to generate captions for incoming audio and video materials. This allows:
A significant reduction in manual labor for our DPS team
The potential for faster turnaround on caption requests
A scalable solution for future projects involving large media archives
Conclusion
As libraries continue to manage growing volumes of audio and video content, scalable and accurate captioning has become essential, not only for accessibility, but also for discoverability and long-term usability. Through this project, we identified WhisperX as a practical open-source solution that significantly improves transcription speed, speaker diarization, and timestamp precision. While no tool is perfect, WhisperX offers a strong foundation for building more efficient and inclusive media workflows in the library setting.
Reflections and Acknowledgements
This project helped me understand just how much thought and precision goes into building effective captioning systems. Tools like WhisperX offer powerful capabilities, but they still require careful evaluation, thoughtful tuning, and human oversight. I am incredibly grateful to have contributed to a project that could drastically reduce the time and effort required to caption large volumes of media, this way enabling broader access and creating long-term impact across the library’s AV collections.
Finally, I would like to thank the Digital Productions Services team for the opportunity and their guidance and support throughout this project — especially Sarah Sweeney, Kimberly Kennedy, Drew Facklam, and Rob Chavez, whose insights and feedback were invaluable.
Two radio program collections available in the Digital Repository Service (DRS) — Issue and Inquiry and Urban Confrontation — document social progress and unrelenting difficulties within American cities in 1970-71. Airing on Northeastern University’s radio station WRBB, the programs were produced the university’s now-defunct Division of Instructional Communication. (Urban Confrontation noted that it ended in 1971 for financial reasons.)
Episodes were primarily hosted by Joseph R. Baylor and feature interviewees from across the United States discussing wide-ranging topics. From the threat of nuclear warfare to the farm labor rights movement, from the “longhair” youth subculture to de-facto school segregation, these episodes present a sweeping view of both common anxieties and optimistic ideas about the future of city life.
As a metadata assistant in Digital Production Services, I performed a survey of the episodes and their associated metadata records. This helped me understand how descriptive information should appear in the DRS. For example, I investigated how titles, creators, subjects, and abstracts should be recorded for each episode. Next, I created an editing plan, performed batch edits, and carefully listened to each episode. As I listened, I recorded accurate information about the episodes so it could be updated in the DRS.
I selected two interesting episodes to highlight here, but be sure to check out the full collection for more episodes.
In this episode from 1970, Al Weingand, Bob Solan, and Dick Smith discuss a Union Oil offshore drilling well explosion that occurred on January 28, 1969, expelling two million gallons of uncontrolled oil into Santa Barbara Channel off the coast of California. Topics include the oil’s effect on tourism, local economy, wildlife, fishing, and environmental safety concerns.
Weingand, a Santa Barbara resident and former California legislative member, explains that no other disasters can compare to the devastation of the oil pollution. Smith, a reporter for the Santa Barbara News Press, calls for greater investment in tourist value of beaches, saying that offshore oil well spills are dangerous both environmentally and economically. Solan, another reporter for the News Press, covers the psychological benefits of beautiful surroundings for Santa Barbara residents.
This episode was produced in a time of evolving standards for environmental safety and presents an intimate view of lives affected by oil pollution.
“The business that I am about is resurrecting that dormant conscious pride that Black people have had and should have.” — Elma Lewis (4:57)
In this episode, airing in 1970, arts educator and activist Elma Lewis discusses the intertwined histories of Black labor and Black cultural impact in America. She speaks critically of modern art because she says it lacks a basis in life experience. This, Lewis explains, is why Black contributions to American culture transcend art and extend to labor and life experience, which has formed the basis of American society. Throughout the program, Baylor asks Lewis to respond to common racist comments about Black culture. Despite Baylor’s insistence that Lewis speak to his white audience, she intentionally denies this request. Laughing, she replies, “I don’t answer nonsense. I’m not in the business of answering nonsense.”
I wanted to highlight these two episodes because they made me think deeply about both everyday problems and large socio-political injustices which continue to affect us today. “Oil in Santa Barbara” presents opinions from concerned community members in California. It focuses on their reaction to environmental pollution, showing common anxieties about business success, health, and the beauty of their local natural environment. By contrast, “Afro-American Culture” features distinguished Black arts educator Elma Lewis. She discusses fine arts movements, while also celebrating Black joy and artistry in the face of wide-scale systemic racism.
I greatly enjoyed the opportunity to help make these shows available in the DRS. Both Issue and Inquiry and Urban Confrontation hold potential research value for those interested in viewing snapshots of American life in the early 1970s.
Chelsea McNeil served as a part-time metadata assistant in Digital Production Services.
The Digital Repository Service (DRS) is an institutional repository that was designed by the Northeastern University Library to help members of the Northeastern community organize, store, and share the digital materials that are important to their role or responsibilities at the university. This can include scholarly works created by faculty and students; supporting materials used in research; photographs and documents that represent the history of the community; or materials that support the day-to-day operations of the university.
While the DRS itself is a technical system that stores digital files and associated information to help users find what they need, we also consider the DRS to be a service for the university community: library staff are here to help you organize, store, share, and manage the digital materials that have long-lasting value for the university community and beyond.
Published research from the Northeastern community available in the DRS.
Northeastern is not alone in this endeavor. Repository services are now standard practice for most academic institutions, including Harvard University Library (who also use the name “Digital Repository Service”), Stanford University Library (a leader in technical development for repository systems), Tufts Libraries, and other institutions around the world.
Who uses the DRS?
The DRS has been used by faculty, staff, students, and researchers from all corners of the university community for 10 years. There are too many use cases to mention in one brief blog post, but here are some trends we’ve seen in what users choose to deposit the last few years.
Publications and data that supports published research
Event recordings, photographs, newspapers, and almost any kind of material you can think of to support the day-to-day operations and activity at the university
Student research projects and classwork, like oral histories and research projects. Students are also required to contribute their final version of their thesis or dissertation.
Digitized and born-digital records from the Archives and Special Collections, including photographs, documents, and audio and video recordings
These files, and all the other audio, video, document, and photograph files in the DRS, have been viewed or downloaded 11.2 million times since the DRS first launched in 2015. Nearly half of the files in the DRS are made available to the public and are therefore available for the wider world to discover. Materials in the DRS have been cited in reporting by CNN, Pitchfork, WBUR, and Atlas Obscura, among others, and are regularly shared on social media or in Reddit threads. As a result, Northeastern continues to contribute the work produced here to the larger scholarly and cultural record, and to the larger world.
Who supports the DRS?
The day-to-day work managing, maintaining, and supporting users of the service comes from staff in Digital Production Services:
Kim Kennedy supervises the digitization of physical materials and processing of born-digital and digitized materials.
Drew Facklam and Emily Allen create and maintain the descriptive metadata that helps you find what you need.
And all of us in the department, including part-time staff, are responsible for general management of the system, including batch ingesting materials, holding consultations and training sessions, answering questions, and leading conversations about how to improve the system and the service.
Sarah Sweeney and David Cliff, DRS staff, posing in 2015 with the homepage of the recently launched DRS.
The DRS is also supported by a number of library staff members across the library:
David Cliff, Senior Digital Library Developer in Digital Infrastructures, is the DRS’ lead developer and system administrator.
Ernesto Valencia and Rob Chavez from the Library Technology Services and Infrastructure departments also provide development support and system administration.
Many librarians in the Research and Instruction department do outreach about the service and support faculty as they figure out how to use it in their work.
Jen Ferguson from Research Data Services also connects faculty and researchers to the DRS, while also providing data management support for those wishing to use the DRS to store their data.
Members of the library administration, including Dan Cohen, Evan Simpson, Tracey Harik, and the recently retired Patrick Yott have contributed their unwavering support and advocacy for developing and maintaining system an service.
We are all here to help you figure out how the DRS may be used to make your work and academic life easier. To dive deeper into what the DRS is and how to use it, visit the DRS subject guide or contact me or my team.
Northeastern University Library’s institutional repository, the Digital Repository Service, is celebrating 10 years of caring for the university’s scholarly, archival, and administrative high-value materials. From day one, the mission of the DRS has been to provide a long-term, sustainable home for the born digital and digitized content being produced by members of the Northeastern community.
More than just a technical system, the DRS is a service provided by the library to help solve a common problem for faculty, staff, students, researchers, and project teams: where can I store the digital output from my work? The DRS allows these projects developed at Northeastern to be maintained and shared with a wider audience. In addition to maintaining the DRS system, services provided by DRS staff include running training sessions, answering questions, consulting, and depositing files for users.
Originally developed as a prototype in 2011, the system was created by a library team — three developers, the repository manager, a Northeastern co-op, and a library administrator — with the goal of constructing a completely realized system ready for production. The first version was ready to be used fully by the Northeastern community in June 2015.
The DRS was launched with some rough edges, which were slowly smoothed into the system users are familiar with today. We have received tremendous response from users about the usefulness of the system, as well as thoughtful and constructive feedback about how the system can be improved (e.g. faster page load times, better search functionality, and more control over files, among others).
The DRS, as it appeared in 2015.
We have done our best to grow with the university community as its needs shift by increasing support for datasets, loading large batches of files on behalf of users and project teams, and tripling our original storage capacity, but there is always more to be done to meet the needs of our users.
The shape of the content stored in the DRS has shifted over the years, as well. Initially just for theses and dissertations, university photographs, and archival material, the DRS now fully supports various types of project materials for digital humanities research, datasets for researchers in various disciplines, oral histories, and many others.
Since its launch, DRS content has been viewed, downloaded, or streamed more than 1.1 million times, and we’ve had more than 13,000 members of the Northeastern community sign into the system. The DRS averages approximately 2,000 unique visitors and 4,000 views, downloads, and streams a day.
The DRS provides a home for and access to research and projects by members of the Northeastern community.
The success of the system can be attributed to the combined efforts of staff in many library departments, including development and system administration from Library Technology Services and Digital Infrastructures; outreach and faculty support from Research and Instruction; data management support from Research Data Services; issue triage and metadata collaboration with Resource and Discovery Services; and continual support and advocacy from library administration. And, of course, Digital Production Services, the department primarily responsible for maintaining the system and supporting the service through digital production, metadata maintenance, and user support.
The DRS is not the first system of its kind supported by the library. It adopted its first repository system in the early 2000s, followed by IRis in 2007. The library’s commitment to maintaining the scholarly output of the university was formed during those early years, a commitment we have refined and strengthened over the more than 20 years of dedicated support for faculty, staff, and students working to help fulfill the university’s mission. It’s been a great pleasure to support the Northeastern community in this way, and we look forward to the next 10 years and beyond.
