Just how vocally demanding are roles in Broadway musicals like “Hamilton” and “Dear Evan Hansen” — and how much singing is too much? If two professors at New York University had their way, Broadway singers would soon have access to a “vocal Fitbit” that could help them answer those questions.

Listen to this week’s “Stagecraft” podcast below:

“Similar to how your iPhone nowadays tells you, ‘Oh, you listened to music a little too loudly this week; watch out, because we don’t want you to get a hearing impairment due to overuse’ — it would be the same idea [but] for the voice,” said Ana Flavia Zuim, a musician and conductor who is also the associate director of vocal performance at NYU’s Steinhardt School. “It could tell you, ‘We see that you’ve used [your voice] up to a particular amount that has been considered a safe threshold of use.'”

Zuim appeared on the new episode of Stagecraft, Variety‘s theater podcast, with her colleague Celia Stewart, associate professor of communicative sciences and disorders. The two were co-authors on a recent study in which an early iteration of a “vocal Fitbit” was used to measure the demands — the “vocal dose” — placed on six musical theater students during rehearsals for a production of Frank Wildhorn’s “Wonderland.”

The test was the first step in filling in some of the information about vocal health that still isn’t known — including what levels of usage and intensity cause damage. “As we better understand dose and voice use, we may be able [someday] to have guidelines that say, ‘Maybe you should only do six shows a week; maybe that seventh or eighth show should be done by somebody else,'” said Stewart.

Stewart and Zuim delved into the specifics of their study on the new Stagecraft, and also explained how they think it can help professional singers and the industry overall. “What we don’t know yet is how much is too much, and how many hours does it take for all the [vocal] fibers to recover,” Zuim said. “This research can lead into further understanding of what those parameters are.”

She added, “The lack of knowledge and understanding of how usage can be impactful to voices leads to this stigma of: If you have an injury, then you don’t have good technique or you are abusing your voice. It imposes on the singer a guilt about something that is simply a part of their journey. You don’t tell a soccer player that they busted their knee because they don’t have proper technique.”

Also on the new Stagecraft, the two professors delved into the evolution of Broadway singing, explained how belting works and shared some factoids gleaned from their research. “Across the six individuals over four days each, their vocal folds did about 20 million vibrations over eight hour periods,” said Stewart. “If you added the distance that the vocal folds moved on each vibration, it added up to about five miles.”

To hear the full conversation, listen at the link above or download and subscribe to “Stagecraft” on podcast platforms including Apple PodcastsSpotify and the Broadway Podcast NetworkNew episodes of “Stagecraft” are released every other week.