neecy
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I participated in this study last spring, and was asked in the "Helping the Deaf Hear Music" thread if I would share them. Since I didn't want to completely hijack Miss-Delectable's thread, I thought it prudent to make a separate post for the study results.
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In February 2007, the Cochlear Implant Program at St Paul's Hospital (Vancouver, BC) obtained approval for participating, with Cochlear Americas, in a multi-center study to look at the musical perception abilities of people with cochlear implants. The study involved 13 cochlear implant centers in the US and Canada, and 17 patients from our Cochlear Implant Program participated.
The majority of the implant recipients who participated hear with a cochlear implant alone, whereas a small number of participants us a CI in one ear, and a hearing aid in the other ear.
The study protocol consisted of 3 tests: pitch discrimination, melody recognition, and musical instrument recognition( also known as timbre recognition.) For the pitch discrimination test, pairs of tones differing in frequency were presented, and the subjects were required to determine which of the 2 tones had the higher pitch. This was tested over 3 frequency ranges, just above “middle C.”
For the melody recognition test, subjects were presented with a list of 12 common melodies, and after a brief practice session, were asked to identify the melodies. The melodies, even when heard by people with normal hearing, did not sound like the melodies as they are normally played or heard, because all the long notes in each melody were divided into a sequence of shorter notes. The third test consisted of a short, 5-note melodic segment, played by one of 8 different instruments. Subjects were provided with a list of 8 possible instruments, and to offer their best guess about the identity of the instrument that was heard in each rendition.
Study Results
Pitch Discrimination:
Pitch discrimination is important in music because it is essential for melody recognition (i.e.,it is important to know whether pitches are going up or down.) Many of the pitch changes in melodies are relatively small, and the question is whether people with cochlear implants are able to detect such small pitch changes. The smallest pitch interval that our 17 subjects in this study were able to discriminate ranged from 0.6 semitones to 11 semitones (i.e., almost an octave,) with an average of 2.3 semitones. Seven of the 17 were unable to detect pitch changes of less than 2-7 semitones. People who had difficulty hearing small pitch changes also tended to have greater difficulty with melody recognition.
Melody Recognition:
This was a very difficult and frustrating test for our subjects. Most people who took the test found the altered rhythmical pattern of the melodies very confusing, and reported that this made recognition of the melodies much more difficult, compared to melody recognition in normal, everyday listening. The scores on this test, for our 17 subjects, ranged from 8% to 94%, with an average score of 26.2%. While the highest score is a remarkable 94%, the second highest score was 44%. Four people scored between 30-36%, and 8 subjects scored less than 20%. While these test scores were generally poor, it is important to remember that these melodies sounded very different from the way these melodies are normally heard. In everyday listening, melodies are heard in their normal, rhythmical contexts, and this would make melody recognition, even for people with cochlear implants, much easier than it was on this test.
Timbre (Musical Instrument) Recognition:
This too, was a very difficult test for all subjects. However, it is important to keep in mind that not everyone with normal hearing would score 100% correct, on this test. The scores, for our 17 subjects with cochlear implants, ranged from 17% to 67%, with an average score of 36.5%. Of our 17 subjects, 4 scored 50% or better, 3 subjects scored 40-50%, 3 scored 30-40%, another 3 scored 20-30%, and 3 scored less than 20%. Obviously, musical instrument recognition can be difficult for people with cochlear implants. However, in everyday listening, musical instrument recognition is likely to be easier than it was on this test. This is because, for every test, every instrument played the same 5-note sequence, whereas in everyday listening, different instruments are heard over a wider pitch range, and the pitch is certainly an important clue for instrument recognition. In normal every day listening, there are many other clues to instrument identity, and thus, we are not surprised that some people with cochlear implants say that, in everyday situations, they are able to recognize musical instruments quite well.
Nevertheless, even though the results were quite varied, this study has given us important baseline information about 3 aspects of the musical hearing capabilities in a large sample of people with cochlear implants. These results will be useful for comparison with future speech processors and processing strategies, as we work to improve not only the speech understanding abilities of people with cochlear implants, but also the musical hearing abilities. However, much work will need to be done before better processing of music will become a reality.
The results compiled here are for the study at St Paul's clinic alone, and do not include the results of the other clinics who have also participated in the study.
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Music Perception Study: The Perception of Musical Pitch Intervals
and Variably Tuned Melodies by Subjects with Cochlear Implants.
by Cochlear Americas.
and Variably Tuned Melodies by Subjects with Cochlear Implants.
by Cochlear Americas.
In February 2007, the Cochlear Implant Program at St Paul's Hospital (Vancouver, BC) obtained approval for participating, with Cochlear Americas, in a multi-center study to look at the musical perception abilities of people with cochlear implants. The study involved 13 cochlear implant centers in the US and Canada, and 17 patients from our Cochlear Implant Program participated.
The majority of the implant recipients who participated hear with a cochlear implant alone, whereas a small number of participants us a CI in one ear, and a hearing aid in the other ear.
The study protocol consisted of 3 tests: pitch discrimination, melody recognition, and musical instrument recognition( also known as timbre recognition.) For the pitch discrimination test, pairs of tones differing in frequency were presented, and the subjects were required to determine which of the 2 tones had the higher pitch. This was tested over 3 frequency ranges, just above “middle C.”
For the melody recognition test, subjects were presented with a list of 12 common melodies, and after a brief practice session, were asked to identify the melodies. The melodies, even when heard by people with normal hearing, did not sound like the melodies as they are normally played or heard, because all the long notes in each melody were divided into a sequence of shorter notes. The third test consisted of a short, 5-note melodic segment, played by one of 8 different instruments. Subjects were provided with a list of 8 possible instruments, and to offer their best guess about the identity of the instrument that was heard in each rendition.
Study Results
Pitch Discrimination:
Pitch discrimination is important in music because it is essential for melody recognition (i.e.,it is important to know whether pitches are going up or down.) Many of the pitch changes in melodies are relatively small, and the question is whether people with cochlear implants are able to detect such small pitch changes. The smallest pitch interval that our 17 subjects in this study were able to discriminate ranged from 0.6 semitones to 11 semitones (i.e., almost an octave,) with an average of 2.3 semitones. Seven of the 17 were unable to detect pitch changes of less than 2-7 semitones. People who had difficulty hearing small pitch changes also tended to have greater difficulty with melody recognition.
Melody Recognition:
This was a very difficult and frustrating test for our subjects. Most people who took the test found the altered rhythmical pattern of the melodies very confusing, and reported that this made recognition of the melodies much more difficult, compared to melody recognition in normal, everyday listening. The scores on this test, for our 17 subjects, ranged from 8% to 94%, with an average score of 26.2%. While the highest score is a remarkable 94%, the second highest score was 44%. Four people scored between 30-36%, and 8 subjects scored less than 20%. While these test scores were generally poor, it is important to remember that these melodies sounded very different from the way these melodies are normally heard. In everyday listening, melodies are heard in their normal, rhythmical contexts, and this would make melody recognition, even for people with cochlear implants, much easier than it was on this test.
Timbre (Musical Instrument) Recognition:
This too, was a very difficult test for all subjects. However, it is important to keep in mind that not everyone with normal hearing would score 100% correct, on this test. The scores, for our 17 subjects with cochlear implants, ranged from 17% to 67%, with an average score of 36.5%. Of our 17 subjects, 4 scored 50% or better, 3 subjects scored 40-50%, 3 scored 30-40%, another 3 scored 20-30%, and 3 scored less than 20%. Obviously, musical instrument recognition can be difficult for people with cochlear implants. However, in everyday listening, musical instrument recognition is likely to be easier than it was on this test. This is because, for every test, every instrument played the same 5-note sequence, whereas in everyday listening, different instruments are heard over a wider pitch range, and the pitch is certainly an important clue for instrument recognition. In normal every day listening, there are many other clues to instrument identity, and thus, we are not surprised that some people with cochlear implants say that, in everyday situations, they are able to recognize musical instruments quite well.
Nevertheless, even though the results were quite varied, this study has given us important baseline information about 3 aspects of the musical hearing capabilities in a large sample of people with cochlear implants. These results will be useful for comparison with future speech processors and processing strategies, as we work to improve not only the speech understanding abilities of people with cochlear implants, but also the musical hearing abilities. However, much work will need to be done before better processing of music will become a reality.
The results compiled here are for the study at St Paul's clinic alone, and do not include the results of the other clinics who have also participated in the study.
