9:02 AM PT -- NASA released a statement on its findings regarding the strange sound heard by astronaut Butch Willmore, stating, "A pulsing sound from a speaker in Boeing’s Starliner spacecraft heard by NASA astronaut Butch Wilmore aboard the International Space Station has stopped. The feedback from the speaker was the result of an audio configuration between the space station and Starliner."

The statement continued, "The space station audio system is complex, allowing multiple spacecraft and modules to be interconnected, and it is common to experience noise and feedback. The crew is asked to contact mission control when they hear sounds originating in the comm system. The speaker feedback Wilmore reported has no technical impact to the crew, Starliner, or station operations, including Starliner’s uncrewed undocking from the station no earlier than Friday, Sept. 6."

As if being stranded in space for the foreseeable future wasn't enough ... one of the astronauts stuck aboard the ISS just sent NASA audio of an ominous noise coming from their faulty Boeing Starliner aircraft.

In audio first reported by Ars Technica, astronaut Butch Wilmore can be heard communicating with Johnson Space Center in Houston ... telling mission control, "I've got a question about Starliner. There's a strange noise coming through the speaker ... I don't know what's making it."

Mission control configured a way for Butch to play the sound through the phone ... and after one failed attempt at hearing it, mission control confirmed, "Butch, that one came through. It was kind of like a pulsating noise, almost like a sonar ping."

The recording was first captured and shared by Michigan-based meteorologist Rob Dale.

Butch played the audio once again for good measure, telling NASA, “I’ll do it one more time and let you all scratch your heads and see if you can figure out what’s going on."

Houston confirmed they will be passing along the recording and will let Butch know what they find.

As we previously reported ... Wilmore and fellow astronaut Suni Williams have been stranded on the International Space Station since June 6, due to Starliner's thruster troubles and helium leaks ... after what was supposed to be a week-long stay.

Starliner is scheduled to undock from the ISS and attempt to land back on Earth on autopilot.

As for Butch and Suni ... the duo are now set to return to Earth in February, 2025 -- hitching a ride on one of Elon Musk's SpaceX ships.