Hearing aids are designed mainly for optimization for speechinputs.
A hearing aid designed for speech is not optimally setfor music. Since there is a lack of understanding of how toprocess music in hearing aids, music perception studies arestill in the infancy period. As hearing-aid technology has de-veloped lot, interest has grown in musical perception so asto improve the aesthetic sense of hearing-impaired listeners.
Hearing loss can be of three types, namely, conductive hear-ing loss, sensoneural hearing loss and mixed hearing loss.Conductive hearing loss is mechanical in nature. A physicalcondition stops sound from being conducted from the outeror middle ear to the inner ear, where nerves are stimulated tocarry sound to the brain. It can be cured by surgery. Thesensoneural hearing loss is due to the damage to tiny haircells that line the inner ear.
It can be cured by hearing aids.A mixed hearing loss means there is a sensorineural hearingloss along with a conductive hearing loss component. Dueto the spectral dissimilarities between speech and music, mu-sic perception for hearing-impaired listeners is a challengingproblem. In general, perception is a process by which individualsinterpret their sensory impressions in order to give meaningto their environment 1. Speech perception can be seen as thetask of understanding how human listeners recognize speechsounds and use this information to understand spoken lan-guage.
To analyze the music perception with hearing aids, itis important to select the test features that influence the musicperception. In the proposed experiment, music perception isanlayzed using components such as meter, harmony, melody,timbre, musical texture, music in noise and fluctuation pat-tern.Meter is the division of a rhythmic pattern according toequal periods or measures 1. Strong and weak beats in thepattern are grouped into larger units, typically categorized asduple or triple according to whether the measure is organizedin groups of 2 or 3 beats.
In the case of sounds of musicalinstruments, the auditory system exploits the harmonicity inthe tones to combine a set of harmonically related compo-nents into a single sound image 2. The perception of con-sonance and dissonance is closely related to the perception oftonality, especially in the case of aesthetic dissonance 3, 4.The perception of loudness correlates with the amplitude ofan oscillation and pitch correlates with the frequency of anoscillation5. Timbre is the perceptual attribute by which wedistinguish instruments even if they play the same note withthe same loudness 6, 7. Rhythm refers to the temporal or-ganization of events as the music unfolds in time 8. Thenumber of individual musical lines (melodies) and the rela-tionship of these lines in a musical piece is denoted by the feature, texture. Fluctuation pattern refers to the amplitudemodulation of loudness at different frequency levels. Sincethe physical and cognitive nature of music comprises simulta-neous and sequential components, music perception is unique8.
A music perception test is conducted in the proposedevaluation. It comprises test to analyse the five attributes,namely, meter, timbre, texture, fluctuation pattern and noisesensitivity. The music perception test is performed on normalhearing and hearing-impaired group.
The rest of the paper is organized as follows: Section 2discusses the related work. Section 3 describes the proposedmethod with a brief discussion on music attributes focusedin the experiment. The performance evaluation is discussed in Section 4. The analysis of results is given in Section 5.Finally, conclusion is drawn in Section 6