FOREST GROVE, Ore. -- What's that sound?
Neighbors in Forest Grove are puzzled by a high-pitched whistling noise.
Paula Lynch told KATU she's heard the noise about five times in the last several weeks, at all hours of the day.
She recorded a 30-second clip and posted it on social media in hopes that someone would be able to identify the sound.
She told the station the sound seems to be coming from a nearby intersection, but says it's tough to find the source. Sometimes it lasts for seconds, other times for several minutes.
A spokesperson for the local fire departments said they are aware of the sounds, but did not know the source.
The city's public works superintendent told ABC News that it's difficult to "make an educated guess as to what's creating the noise." Officials have ruled out a water valve, a gas leak and wildlife.
Another neighbor, Chester Epperson, told KATU he hadn't heard the sound yet.
"Maybe 'The X-Files' back on TV again," he joked. "High-pitched, it's got a pause. I'll keep my ears out."