The invention provides a canal hearing device and method in which the device
is implemented with a mode of operation that provides acoustic transparency as
well as a power-saving function, particularly useful to permit the user to wear
the device in the ear canal during periods of sleep or inactivity without substantial
loss of normal unaided response. The transparent mode has an in-situ acoustic transfer
function that compensates for the insertion loss caused by the presence of a hearing
device in the ear canal. While the device is in this transparent mode, its acoustic
transfer function gives the user a perception of unaided hearing, as though the
device were removed, when it is actually being worn continuously in the ear canal.
Current drain of the device is significantly reduced as the transparent mode serves
to shut off or reduce bias currents of at least one circuit element within the
device circuitry. The invention is particularly useful in canal hearing devices
adapted for extended wear in the ear canal for periods longer than one month without removal.
