The Brownian or thermal noise limit has been reached up to frequencies of about 50 kHz in air using an axially symmetrical two-beam interferometer whose pellicle beamsplitter bulges under sound pressure. Frequency spectra of the Brownian noise observed in hydrogen, air, and CC12F2 are shown to be correlated to cavity resonant modes (or echoes) within the microphone.
Click to purchase paper as a non-member or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!
This paper costs $33 for non-members and is free for AES members and E-Library subscribers.