” Your most dissatisfied customers are your greatest source of learning. “
Bill Gates
There is no inherent reason why the vocal output of an English speaker should be any different from a person speaking Chinese. However, the frequency band importance of a Chinese speaker has greater value in the lower frequencies than for English because Chinese relies more on pitch changes in the lower-frequency vowels.
Indeed, the Chinese as 60% of the languages in the world are said tonal language, in which the pronunciation of the syllables of a word is subjected to a precise tone, that is to say to a determined relative height or a characteristic melody. A modification of this tone then leads to another word and another meaning.
The hearing aids distributed in these countries, which count in the hundreds of millions of people, are identical to those adapted for populations with atonal languages. This results in a great dissatisfaction of the hearing impaired, confirmed by the audiologists themselves. According to EHIMA Japan Track 2015, overall satisfaction in Japan with hearing aid is 39% only.
Indeed, if hearing loss affects all humans worlwide physiologically and statistically at first on high frequencies, it is not by amplifying these frequencies, however deficient that the intelligibility of individuals speaking a tonal language will be optimized.
While there is an official “tonal languages” option in the National Australian Laboratories’ NAL-NAL calculation formulas for digital hearing aids, this only works significantly on low frequencies, which are slightly enhanced for the occasion.
To optimize the acoustic indices that make the intelligibility of tonal languages, it is indeed necessary to be able to highlight formants and formal transitions F0, F1 and F2 which are observed between 100Hz and 900Hz.
FrenchEar’s acoustic-linguistic conclusions on the specific key indexes of these languages have had a direct impact in the strategy of evolution in the technologies implemented for future FrenchEar devices. Based on linear adjustments to low frequencies thanks to its analog amplification allowing an excellent bass dynamics, FrenchEar will cleverly work to highlight the variations of the formal transitions of these fundamental tonal language frequencies whose relative height of sound affects the meaning of the words themselves.
Citations for this article:
Chasin M. How hearing aids may be set for different languages. Hearing Review. 2008;15(11):16-20
EHIMA, Results JapanTrak 2018
National Acoustic Laboratories (NAL) // www.nal.gov.au
