A B757 Flight Attendant reported a high pitch noise from door 1R; an inability to clear his ears and feeling light headed. After the oxygen masks dropped the Captain announce they were returning to the departure airport.

Narrative

[We] reached cruising at 32;000 FT; starting First Class service. Forward service door 1R had high pitch noise. I thought it was more so than normal because I couldn't clear my ears. I (#3) was feeling a bit light headed and was getting a headache. I called the Captain to notify of noise from door. Then I walked out in cabin and it was extremely hot temperature in cabin; more than normal. Flight Attendant #1 and I returned to jump seats. [We] called other Flight Attendants in back to take jump seats. Flight Attendant #1 tried calling cockpit but no response. Just noticed we were descending. Once we got Captain on phone; noticed he was on Oxygen; but our masks had not deployed. Once they did (my oxygen at jump seat did not open) had to go to First Class and stand in aisle to get O2. PA made to put on masks. I showed and helped First Class passengers put on masks. Once I got the O2 walk around on; I was able to help passengers to mask. Passengers and Flight Attendants remained on O2 until 10;000 FT. Captain made announcements we would be landing back at our departure airport in 10 minutes. Passengers remained calm; some remained on O2 until we landed; no injuries; no planned emergency; normal landing procedures.