Ear phone, telephone handset and head phones for correcting individual hearing deficiencies

摘要

An earpiece comprises a suction cup sensor, a preamplifier, a potentiometer for varying the gain of the amplifier, a pass band filter and electronic means enabling the user to adjust the central frequency and/or width of the pass band of the filter. One application of the invention is the construction of self-contained and individualized telephone handsets or headphones which may be connected without any wire connection on any telephone set.