delta audiology concept
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-10 0 10 20 30 40 50 60 70 80 90 100 110 120 db hl -10 0 10 20 30 40 50 60 70 80 90 100 110 120 db hl 125 250 500 1000 2000 4000 8000 hz 125 250 500 1000 2000 4000 8000 hz hearing loss speech spectrum background noise the needs the needs despite the availability of increasingly advanced technology the average age of first time users has shown little change over time 1 in other words the industry has not been able to attract more new users one of the strongest desires for many years younger first time users present us with a number of audiological challenges while they have good loudness sensation and hearing in the lower frequencies their loss is restricted to the high frequency region figure 1 good low frequency hearing leads to near normal speech understanding for many communication situations 2 these situations are typically one-toone conversations where visual cues are abundant and background noise is rare in noisy situations however the loss of high frequency information is esp
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delta vs typical thin tube 80 iec 60711 coupler output db spl results in poorer sound quality clearly the best solution is to bypass the need for compensation and corrections and to place the receiver in the ear canal a key concept in delta is to allow the user access to an extended high frequency bandwidth this is the key to better speech understanding figure 4 highlights the speech intelligibility in noise improvement that can be gained from increasing the high frequency bandwidth from 6000 to 8000hz on a test of consonant identification it can be seen that 10 of 11 participants showed a significant improvement in access to speech information in a speech reception threshold srt test examination of specific speech sounds showed an overall accuracy improvement but also access to high frequency consonants such as /s were improved with an extended high frequency bandwidth this increased access to high frequency speech energy not only increases speech understanding in noise but also reduc
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50 db iec 645.2 speech noise insertion gain 20 20 80 db iec 645.2 speech noise insertion gain insertion gain db 10 insertion gain db 15 15 10 5 5 0 100 -5 1000 10000 0 100 1000 10000 frequency hz delta 8000 typical ite figure 6 frequency responses showing the unique clarity gain and compression strategy in delta at soft inputs clarity prescribes less gain than a conventional solution to preserve comfort -5 frequency hz delta 8000 typical ite figure 7 at loud inputs i.e speech in noise clarity benefits from the extended bandwidth in delta to deliver extra high frequency amplification to improve speech understanding mixing of the direct sound and amplified sound this mixing of sound sources results in the need to develop a totally different amplification strategy and provides the possibility to provide less gain than would ordinarily be prescribed in traditional hearing loss compensation strategies therefore it is crucial to design the rationale with both the user s need for speech under
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20 15 insertion gain db 10 in delta an exchangeable top grid above the microphones acts as a combined wind and dirt protection figure 10 this grid acts by significantly slowing down velocity of the air just in front of the microphones thus lowering the impact of wind importantly the patented grid was designed to ensure high directivity while directionality provides many advantages it is not however the solution for every possible listening environment 17 18 therefore delta is driven by artificial intelligence that calculates the signal-to-noise for any given listening situation and ensures that directionality will provide a benefit before enabling the system this removes the unfortunate situations known from other systems where important signals from behind are cancelled similarly the wearing of full time directional system provides an audible distortion to the listener s sound scene thus providing further loss of transparency artificial intelligence is the key is to ensure that the
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10 very good 10 conclusion delta provides an unrivalled degree of performance for people with a mild to moderate high frequency hearing loss importantly the cosmetic benefits and size do not come at the cost of other features or sound processing options the approach taken by delta is audiologically novel the purpose is not to fully correct for the hearing loss but to focus on providing the best possible speech understanding in difficult listening situations in this way delta meets the needs of people who have good low frequency hearing and a mild to moderate high frequency hearing loss clarity of speech listening comfort overall delta conventional dsp listening effort 10 9 8 5 aceptable 5 needed effort 7 6 5 4 3 2 1 0 0 very poor 0 unaided similarly in addition to refocusing our thoughts in terms of sound processing delta also augments the clarity rationale with the most advanced automatic features multiband adaptive directionality and tristate noise management governed by the only hea
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we believe that it takes more than technology and audiology to create the best hearing instruments that s why we put the individual needs and wishes of people with hearing loss first in our development of new hearing care solutions www.oticon.com 910 12 410 00/02.06 printed in denmark
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