SHD
Selective Hearing Device

LIPPS have developed a selective hearing device (SHD) to assiste any situation were a selective hearing is needed or useful for badly hearing or deaf people. Also, it should be useful for any, even well hearing person, in situations where, for example, one wants to listen somebody in a very noisy environments or in the presence of many other speaking people, etc. If your computer has a sound card on board and sound playing software installed you can listen two examples of the effect.

1. A pure melody coming from some direction (10^o) on the background of a strong wite noise coming from another direction (0^o) would be listened as the melody in noise. Nevertheless if one uses SHD, the music will be listened as cleared melody on the background of some light noise.
2. Three national russian songs "Troyka", "Moroz - moroz" and "Oy da ne vecher", coming from three different directions (0^o, 30^o, 70^o) on the background of a light undirected wite noise would be listened as a song mixture. SHD segregates the songs which will be listened as segregated "Troyka", segregated "Moroz - moroz", segregated "Oy da ne vecher" on the background of some light noise.

The effect is gained by applying the high-resolving digital signal processing techniques to acoustic signals captured and digitalized by a special receiver.

SHD can be implemented as:

• a small electronic device similar to many others devices for deaf people being available on the market,
• head-phones similar to walkmen's models.

SHD supports normally three working modes to be used for variuos situations and environments (the SHD user can switch for his convenient between these modes):

• Undirected hearing (acoustic signals incoming from any direction are listened as is).
• High-directed hearing from the "in front of" direction (acoustic signals incoming from any other direction are suppressed). In this case the user have to look righ to the source he wants to hear. A suitable mode for very noisy environments.
• Low-directed hearing (acoustic signals incoming from some angle sector are listened as is and those from all other directions are uppressed). The user can ajust the hearing secor width. This mode is good for listening concerts, in the theater, etc.