In 1982, Professor William Helmreich released his sociological study of the Yeshiva World, entitled The World of the Yeshiva. The highlight of this work, were the many interviews he conducted with many of the great Roshei Yeshiva of the era (R Schneur Kotler, R Yaakov Perlow, R Yaakov Weinberg, R Elya Svei, R Aharon Schechter, R Osher Kalmanovitz, R Shmuel Berenbaum, R Yaakov Kamenetzky, R Yitzchak Hutner, R Moshe Feinstein, R Gedaliah Schorr, R Mordechai Gifter and R Henoch Leibowitz). Unfortunately those recordings were lost, but the transcripts are available on Hebrewbooks.org. A very worthwhile read.
Professor Helmreich passed away due to Covid-19 complications on March 28 of this year.
Hebrewbooks link
https://drive.google.com/file/d/1TWy1BsxlFIOBzgAcxCCAEwjNvm73QlSS/view?usp=sharing