Telephone handset and acoustic converter for one such telephone handset
A wideband telephone handset is provided with an acoustic converter The acoustic converter is preferably a wideband acoustic converter and the membrane rear volume of the acoustic converter in the rear wall of the housing, thereof comprises openings which open towards the outside of the acoustic converter and from which noise can escape. The rear housing part of the telephone handset includes inner walls forming a type of channel through which the space up to the housing of the telephone handset is sealed in a soundproof manner around the openings of the rear wall of the housing of the acoustic converter. The rear housing part of the telephone handset has openings through which the noise escaping from the rear of the acoustic converter and conducted via the walls of the rear housing part of the telephone handset can be emitted from the telephone handset. These measures enable a low pitch to be increased, such that the wideband criterion is at least practically fulfilled in terms of the lower limiting frequency of the wideband transmission range.
1 - 5 . (canceled)
6 . An acoustic converter for a portable device, comprising:
a housing, comprising a membrane rear volume;
an opening structure, located on the membrane rear volume;
internal walls, located on a rear wall of the device, wherein the internal walls form an acoustic channel through which sound is directed to the opening structure; and
an acoustical blocking element, located over the opening structure, wherein the acoustical blocking element forms an acoustic seal between the opening structure and the rear wall.
7 . The acoustic converter according to claim 6 , wherein the portable device is a telephone
8 . The acoustic converter according to claim 6 , wherein the internal walls comprise at least a single layer.
9 . The acoustic converter according to claim 6 , wherein the internal walls are formed concentrically.