I just do same testimg with different sound drivers, Java version on OS/2 - eCs.
I found the following line in the java console:
java.lang.IllegalArgumentException: No line matching interface SourceDataLine supporting format PCM_SIGNED, 44100.0 Hz, 16 bit, stereo, little-endian, audio data, and buffers of 16384 to 16384 bytes is supported.
at javax.sound.sampled.AudioSystem.getLine(AudioSystem.java:339)
Okay, there is a prolbem beteewn Java and the sound system.
Question:
What sound/sampling rates do you user for mic imput and sound out in the applet?