Electric hearing aid

The method of adapting the frequency response of a hearing aid having plural sound sources each supplying acoustic frequency components covering an overall wideband acoustic frequency range when driven at a maximum output level, and having respective sound transmission channels each receiving the acoustic frequency components covering said overall wideband acoustic frequency range from a respective one of said sound sources, with the respective sound transmission channels having respective outputs and having respective acoustic lengths which can be adjusted to change the relative phases of acoustic frequency components as supplied at said outputs, said method comprising:

• (a) energizing the sound sources with a common range of acoustic frequencies, and supplying to each of the sound transmission channels corresponding acoustic signals having said common range of acoustic frequencies,
• (b) selectively modifying the length of one of the sound transmission channels in comparison to another such that the acoustic frequency components after transmission to the outputs of the respective sound transmission channels have relatively adjusted phases at respective frequencies over the overall wideband acoustic frequency range, and
• (c) combining the acoustic frequency components from the outputs of the sound transmission channels and transmitting a resultant of the combined acoustic frequency components to the ear of a hearing impaired individual,
• (d) the selectively modifying step being carried out such that the resultant of the combined acoustic frequency components has a substantially lower amplitude in one part of the overall wideband acoustic frequency range relative to other parts of said frequency range than the corresponding acoustic frequency components at the output of either of said sound transmission channels.

The method of adapting the frequency response of a hearing aid having plural sound sources each supplying acoustic frequency components covering an overall wideband acoustic frequency range when driven at a maximum output level, and having respective sound transmission channels each receiving the acoustic frequency components covering said overall wideband acoustic frequency range from a respective one of said sound sources, with the respective sound transmission channels having respective outputs and having respective acoustic lengths such that the relative phases of the acoustic frequency components from the respective sound sources can be adjusted as supplied at said outputs, said method comprising:

• (a) supplying driving signals to the sound sources with a common range of acoustic frequencies, and supplying to each of the sound transmission channels corresponding acoustic signals having said common range of acoustic frequencies,
• (b) selectively modifying the phase of the driving signal supplied to one of the sound sources in comparison to another such that the acoustic frequency components after transmission to the outputs of the respective sound transmission channels have relatively adjusted phases at respective frequencies over the overall wideband acoustic frequency range, and
• (c) combining the acoustic frequency components from the outputs of the sound transmission channels and transmitting a resultant of the combined acoustic frequency components to the ear of a hearing impaired individual,
• (d) the selectively modifying step being carried out such that the resultant of the combined acoustic frequency components has a substantially lower amplitude in one part of the overall wideband acoustic frequency range relative to other parts of said frequency range than the corresponding acoustic frequency components at the output of either of said sound transmission channels.

A hearing aid with acoustic signal pickup means, amplification means, and sound reproduction means, said sound reproduction means comprising two sound sources, a common acoustic transmission channel, and sound transmission channels coupling the sound sources with said common acoustic transmission channel, said sound sources each being constructed for supplying acoustic frequency components covering a frequency range of sound to be supplied to the ear of the user, said sound reproduction means providing different sound transmission properties for the respective sound transmission channels such that a selected individually adapted differential transmission of the acoustic frequency components results via the respective sound transmission channels and such that relative amplitudes of the acoustic frequency components result at the common acoustic transmission channel representing a resultant frequency response specifically conformed to the individual hearing impairment of the user in spite of high gain operation of the amplification means, said sound transmission channels having respective different lengths such that the phase of sound transmission along one transmission channel changes by at least 180.degree. compared to the phase of sound transmission along the other transmission channel within the frequency range of acoustic frequency components supplied by said sound sources, said sound sources supplying acoustic frequency components which are in phase, the different lengths of said sound transmission channels being such that low frequency components transmitted by the respective channels combine additively at the common acoustic transmission channel while higher frequency components of said frequency range are out of phase at said common acoustic transmission channel and tend to cancel each other.

A hearing aid with acoustic signal pickup means, amplification means, and sound reproduction means, said sound reproduction means comprising two sound sources, a common acoustic transmission channel, and sound transmission channels coupling the sound sources with said common acoustic transmission channel, said sound sources each being constructed for supplying acoustic frequency components covering a frequency range of sound to be supplied to the ear of the user, said sound reproduction means providing different sound transmission properties for the respective sound transmission channels such that a selected individually adapted differential transmission of the acoustic frequency components results via the respective sound transmission channels and such that relative amplitudes of the acoustic frequency components result at the common acoustic transmission channel representing a resultant frequency response specifically conformed to the individual hearing impairment of the user in spite of high gain operation of the amplification means, said sound transmission channels having respective different lengths such that the phase of sound transmission along one transmission channel changes by at least 180.degree. compared to the phase of sound transmission along the other transmission channel within the frequency range of acoustic frequency components supplied by said sound sources, said sound sources supplying acoustic frequency components which are out of phase, the different lengths of said sound transmission channels being such that the lowest frequency components as transmitted by the respective channels tend to cancel each other at the common acoustic transmission channel while progressively higher frequency components of said frequency range are progressively more nearly in phase so as to be additive at the common acoustic transmission channel.

The method of adapting the frequency response of a hearing aid having plural sound sources each supplying acoustic frequency components covering an overall wideband acoustic frequency range during high gain operation, and having respective sound transmission channels each receiving the acoustic frequency components covering said overall wideband acoustic frequency range from a respective one of said sound sources, with the respective sound transmission channels having respective sound transmission properties which can be selected to adapt the frequency characteristic being supplied to the ear of a hearing impaired individual, said method comprising energizing the sound sources with a common range of acoustic frequencies so as to supply corresponding acoustic signals to the respective sound transmission channels, and selectively modifying the sound transmission properties of one of the sound transmission channels in comparison to another such that the acoustic frequency components after transmission by the respective sound transmission channels have respective different characteristics at respective frequencies over the frequency range to be supplied to the individual, and such that the acoustic frequency components have a combined effect at the ear of the hearing impaired individual which compensates for the specific hearing loss of the individual over said frequency range in spite of high gain operation of the hearing aid, wherein the sound sources are energized to supply corresponding acoustic signals which are out of the phase, the length of one of the sound transmission channels being selected relative to another such that low frequency components of the frequency range tend to cancel at the ear while higher frequency components of the frequency range tend to become additive at the ear of the hearing impaired individual so as to maintain a specific high frequency boost characteristic in spite of high gain operation of the hearing aid.