Earphone unit and a terminal device

A terminal device arrangement which comprises a terminal device which terminal device comprises

• means for two-way transfer of messages, and
• a separate earphone unit connected to an ear, which earphone unit comprises
• sound reproduction means for converting an electric signal into an acoustic sound signal and forwarding it into the auditory tube of the user of the earphone unit, and
• speech detection means for detecting the speech of the user of the earphone unit from said same auditory tube of the user, wherein it comprises means for determining an impulse response between said sound reproduction means and said speech detection means, means for separating sound signals produced into the auditory tube by said sound reproduction means from sound signals detected by said speech detection means based on said impulse response, and means for eliminating sound signals produced into the auditory tube by said sound reproduction means from sound signals detected by said speech detection means.

A method of reproducing voice in a person's ear, said method comprising the steps of:

• placing a transducer unit in or at the person's ear,
• transferring a speaker signal into the person's ear by the transducer unit;
• a speech signal of the person being conducted inside the head from the person's vocal cords to the person's auditory tubes via the person's bone and soft tissue structure in response to speech of the person;
• detecting a sound signal in or at the person's ear by the transducer unit, said sound signal comprising said speech signal and said speaker signal;
• and
• subtracting said transferred speaker signal from said sound signal.

An earphone unit to be connected to an ear, comprising:

• sound reproduction means for converting an electric signal into an acoustic signal and for transferring it further into the auditory tube of the user of the earphone unit;
• and
• speech detection means for detecting the speech of the user of the earphone unit from the user's said same auditory tube, wherein it comprises:
• means for determining an impulse response between said sound reproduction means and said speech detection means;
• means for separating sound signals produced into the auditory tube by said sound reproduction means from sound signals detected by said speech detection means based on said impulse response;
• means for eliminating sound signals produced into the auditory tube by said sound reproduction means from sound signals detected by said speech detection means;
• means for dividing the frequency band utilised by sound signals produced by said sound reproduction means and sound signals detected by said speech detection means into at least two parts;
• and
• predicting means for predicting missing frequency bands created in connection with said division of frequency bands.