By Carolyn Heneghan
Picture a world where the deaf and hard of hearing can enjoy music just as much as an uninhibited listener. While scientists have made progress toward that goal by enabling the ability to hear and understand speech in quiet environments, hearing music is not yet perfected. But researchers at the University of Washington in Seattle have developed an algorithm for cochlear implants wherein music sounds pleasing, rather than like a jumbled bunch of sounds.
Music in the Cochlear Implant
According to the University of Washington website:
A cochlear implant is a small, electronic device that lets a person who is profoundly deaf or hard of hearing perceive sound. One piece is placed on the skin behind a person’s ear, while another portion is surgically inserted under the skin. The implant works by directly stimulating the auditory nerve, bypassing damaged portions of the ear. The implant’s signals are sent to the brain, which recognizes the signals as sounds.
The standard implants use a special algorithm to categorize sounds into high, middle and low frequencies. The problem with these standard implants is that the algorithm is too stiff to properly hear music. Regular sounds such as speech are audible, but music’s shifting pitches and the instrumental timbres are too complex to hear. Furthermore, implant users can only hear one voice at a time, as background noise and multiple voices produce a cacophony of sound—another reason why the combinative instrumentation in most music would be difficult to hear.
“If you sing ‘Happy Birthday to You’ to someone who has a cochlear implant, they’ll have no difficulty understanding what you’re saying, but if you play a version that is devoid of lyrics or rhythm, they can’t tell the difference between that and ‘Twinkle, Twinkle Little Star,’” explains Rubinstein, a professor of otolaryngology and bioengineering at the Virginia Merrill Bloedel Hearing Research Center.
He continues, “The other thing they can’t hear is timbre. So we have several instruments play the same five-note sequence and ask them to say what’s the guitar or what’s the piano. Someone who has normal hearing will do this test virtually perfectly, but someone who has a cochlear implant will score very poorly.”
The Researchers’ Laudable, Audible Results
The new algorithm developed by the university changes all of that. Whilst wearing cochlear implants embedded with this music-decoding algorithm, the average implant user scored a 45% on the timbre test, and the test subject who performed the best in the experiment reached nearly 90%. In terms of pitch, the new algorithm could expand most of the test subjects’ recognition of a single octave to three octaves. This advancement coupled with the ability to interpret rhythm and words through natural speech comprehension are pieces of the puzzle to eventually fully hear and understand music.
“If they are hearing a single guitar, they can hear one note,” said Atlas of current wearers. “If a person is playing fast, they can hear that. If a person is playing slow they can hear that.”
These findings suggest a striking improvement in music perception and success in the realm of music listening for the deaf and hard of hearing. According to many researchers in the field, if music becomes audible to a cochlear implant user, then so will virtually any other sound, meaning a huge step forward not only in music-listening for the deaf but also in their abilities to hear background noise or multiple voices.
The next step of the project is to enable listeners to interpret melody, which is currently difficult even with this latest algorithm. The researchers also specifically catered their algorithm design to update existing cochlear implants, so that users could keep their old implants.
Implications of Music in Cochlear Implants
One obvious implication of this new algorithm is that the deaf and hard of hearing will eventually be able to listen to music as a common form of interest and enjoyment. The enrichment that music brings to people’s lives will finally be accessible to those who could not previously perceive it. As the quality of sound from these algorithms improves, the level of experience and relationship that the deaf can have with music increases along with it—a breakthrough that could ultimately change or affect their lives tremendously.
With the ability to hear music comes the ability to create music. While there have been musicians who were hard of hearing, this algorithm and its future improvements will open the doors for millions of people to be able to listen to and create their own music. Can you imagine the works of Beethoven if he had his full sense of hearing? The implications of allowing such a huge new group of people into the music industry will be astounding, and the creativity of those artists may introduce an unprecedented wave of new music.
There also comes the possibility of musicians making music with specific optimization for cochlear implants. This music would be tailored to each level of music comprehension as these calculations are perfected, so that the deaf can too develop the musical skills of someone with full hearing abilities. What this music might sound like can be left to the imagination, but it would not be surprising for musicians to appreciate and become involved with this scientific breakthrough.
The research, findings, and implementations of Les Atlas, Ph.D., Jay Rubinstein, MD, Ph.D and Kaibao Nie, Ph.D at the University of Washington represent huge advancements in cochlear implants thus far, and the potential capabilities therein will be exciting as they are realized in the future.
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