Narrative:

Cruise climb to FL280. Passing FL180 first officer and I started to notice a squealing/high pitched noise coming from my window. Sound volume increased rapidly in the next few thousand feet. At FL210 noise became loud enough to where I had to turn up volume on communication 1 to max to hear and understand ATC. I asked to level off at intermediate altitude to troubleshoot the problem; at that point we were fairly certain it was a pressurization issue so we didn't want to climb any higher and exacerbate [the] problem. We wondered if perhaps the noise was coming from the ramp hail/gpu panel which sometimes lessens if speed is reduced. We reduced speed from 290 to 230 with hardly any change in noise level. Asked first officer to consult QRH for any applicable information but none was discovered that was directly applicable to our situation; as airplane was holding pressure sufficiently at that point in time. Contacted mx and dispatch via acars. Called flight attendant to see if she heard any noise over the interphone or elsewhere but she didn't. The noise was loud enough to where ATC could hear a high pitch whine in our transmissions and was a significant distraction for us as a crew. Mx advised a return to the departure airport. We advised ATC and they gave us a new clearance. We advised ATC that we would have to burn off excess fuel in order to avoid landing overweight. Called flight attendant and briefed her that we would have to return for landing and to prepare cabin. Made a PA and advised passengers that we had a pressurization malfunction and that while we had isolated and contained the problem it was no longer safe to continue the flight to our destination and that we would be returning and be on the ground in approximately 30 minutes.we received a lower altitude; extended the landing gear; and lowered flaps. While burning off excess fuel dispatch contacted us and advised us an overweight landing was approved provided we didn't exceed 360 feet per minute upon touchdown. Texted back to confirm and was reassured that this was approved. Contacted ATC and advised them we could return for landing. Received vectors onto the ILS approach. Touched down very smoothly at zero FPM on vsi; no complications. Advised tower that we didn't require any assistance. Taxied to gate without issue.

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Original NASA ASRS Text

Title: EMB145 Captain reported a possible cockpit window seal issue manifesting as a loud; high pitched noise in the cockpit during climbout. There were no pressurization issues and the aircrew returned to the departure airport.

Narrative: Cruise climb to FL280. Passing FL180 FO and I started to notice a squealing/high pitched noise coming from my window. Sound volume increased rapidly in the next few thousand feet. At FL210 noise became loud enough to where I had to turn up volume on COM 1 to max to hear and understand ATC. I asked to level off at intermediate altitude to troubleshoot the problem; at that point we were fairly certain it was a pressurization issue so we didn't want to climb any higher and exacerbate [the] problem. We wondered if perhaps the noise was coming from the ramp hail/GPU panel which sometimes lessens if speed is reduced. We reduced speed from 290 to 230 with hardly any change in noise level. Asked FO to consult QRH for any applicable information but none was discovered that was directly applicable to our situation; as airplane was holding pressure sufficiently at that point in time. Contacted MX and dispatch via ACARs. Called FA to see if she heard any noise over the interphone or elsewhere but she didn't. The noise was loud enough to where ATC could hear a high pitch whine in our transmissions and was a significant distraction for us as a crew. MX advised a return to the departure airport. We advised ATC and they gave us a new clearance. We advised ATC that we would have to burn off excess fuel in order to avoid landing overweight. Called FA and briefed her that we would have to return for landing and to prepare cabin. Made a PA and advised passengers that we had a pressurization malfunction and that while we had isolated and contained the problem it was no longer safe to continue the flight to our destination and that we would be returning and be on the ground in approximately 30 minutes.We received a lower altitude; extended the landing gear; and lowered flaps. While burning off excess fuel dispatch contacted us and advised us an overweight landing was approved provided we didn't exceed 360 feet per minute upon touchdown. Texted back to confirm and was reassured that this was approved. Contacted ATC and advised them we could return for landing. Received vectors onto the ILS approach. Touched down very smoothly at zero FPM on VSI; no complications. Advised tower that we didn't require any assistance. Taxied to gate without issue.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.