Improper microphone position and speech level on a telephone headset is
sensed by comparison of a speech envelope to multiple signal threshold levels.
A first threshold is used to determine whether a headset user is talking. A second
threshold is used to determine whether a signal level at the microphone is sufficiently
strong for proper communication. An indicator is activated when the user is talking
and the signal level is too weak. Typically, a weak signal is caused by a mispositioned
microphone or a user talking too softly.