Results of auditory rehabilitation in elderly users of hearing aids evaluated by a dichotic test

Purpose: To verify the effects of auditory rehabilitation through the analysis of quantitative and qualitative aspects of the Staggered Spondaic Word Test (SSW) in elderly people who have recently started wearing hearing aids. Methods: The study included 17 elderly people, who have recently started wearing hearing aids, aged between 60 and 84 years old, divided into two groups: G1, for those who only wore hearing aids, and G2, for those submitted to an auditory rehabilitation program structured in seven sessions, including auditory counseling and training. All subjects were evaluated with the SSW test at two different moments, the beginning and the end of the study. All data were statistically analyzed. Results: Regarding quantitative aspects, subjects in G1 showed improvements, but no statistically significant differences were observed between evaluations, while G2 presented statistically significant improvements on the competitive right, the non-competitive left and the total number of hits. When comparing the final performance of both groups, there were statistically significant differences concerning almost all of the variables with greater results to the G2 group. Regarding qualitative aspects, volunteers in both groups had difficulties with phonemic decoding, gradual memory loss, organization and integration in both assessments, with different alterations between them. Conclusion: The scores obtained by subjects in G2 submitted to the hearing rehabilitation in the variables competitive right and left non-competitive show especially the improvement on the left hemisphere, due to auditory training. For further evidence of differences between the results of qualitative aspects, a longer period of time would possibly be required in order for changes in auditory perception to occur associated with other sensory functions. 170 Lessa AH, Hennig TR, Costa MJ, Rossi AG CoDAS 2013;25(2):169-75 INTRODUÇÃO As diversas mudanças orgânicas e fisiológicas que ocorrem no sistema auditivo dos idosos, tanto na porção periférica quanto central, possivelmente interferem na habilidade desta população de processar eficientemente os estímulos de fala que recebe, gerando com frequência dificuldade na compreensão de fala, que pode ser agravada na presença de perda auditiva. A presbiacusia se caracteriza por ser uma perda auditiva progressiva da sensibilidade auditiva em função da idade, que pode começar a qualquer momento, mas é mais esperada que ocorra a partir dos 60 anos de idade. Tradicionalmente, é caracterizada como uma perda auditiva bilateral e mais acentuada nas frequências altas; os resultados do Índice de Reconhecimento de Fala (IRF) variam muito, dependendo do local da lesão; o recrutamento pode ou não estar presente; os reflexos acústicos estão ausentes, ou presentes quando ocorre recrutamento. A prótese auditiva pode ser utilizada para reabilitar o idoso portador de perda auditiva, mas apesar de amplificar e modificar os estímulos acústicos de acordo com as necessidades de cada sujeito, e resgatar a percepção dos sons do ambiente e da fala, não modifica diretamente o cérebro ou o comportamento do usuário. Assim, embora a audibilidade de um sinal de fala possa ser restaurada imediatamente, após a adaptação de próteses auditivas, o usuário necessita de um tempo para aprender a interpretar as informações acústicas introduzidas recentemente. Logo, a realização de um treinamento com o indivíduo pode ser necessário para otimizar os benefícios das próteses auditivas, aprimorando as habilidades de reconhecimento de fala. Um estudo sugeriu que acompanhar o paciente apenas até o momento da aquisição das próteses não é suficiente e referiu a importância de o paciente sentir-se amparado e ter uma boa interação com o fonoaudiólogo. Além disso, como foi percebido em outra pesquisa, por meio de sessões de aconselhamento pode ser verificada a segurança e a confiança dos indivíduos para desempenharem uma boa comunicação, assim como para manusear e cuidar das próteses auditivas. O treinamento auditivo formal para idosos é possível, porém as tarefas que envolvem condições de escuta difícil podem causar frustração, desânimo e desistência do treinamento, com consequente abandono do uso da prótese auditiva. Assim, procurou-se desenvolver um programa de treinamento auditivo que pudesse ser mais interessante, lúdico e prazeroso para idosos usuários de próteses auditivas, o Treinamento Auditivo Musical (TAM). Neste treinamento, a autora buscou oferecer estímulos desafiadores em tarefas motivadoras e que se repetem, a fim de favorecer o desenvolvimento da plasticidade neural. Para a avaliação das mudanças advindas da estimulação auditiva no desempenho comunicativo dos sujeitos, o pesquisador pode-se valer de diferentes avaliações. No presente estudo, utilizou-se o teste conhecido como SSW (Staggered Spondaic Word Test) ou Teste Dicótico de Dissílabos Alternados, em português brasileiro adaptado, que avalia diferentes habilidades por meio da tarefa de audição dicótica. Sendo assim, este estudo teve como objetivo verificar os efeitos da reabilitação auditiva, por meio da análise dos aspectos quantitativos e qualitativos do teste SSW, em idosos novos usuários de próteses auditivas.


INTRODUCTION
The different organic and physiological changes that occur in the auditory system of the elderly, both in the peripheral and central regions, possibly interfere with the ability of this population to efficiently process the received speech stimuli, thus leading to difficulties in oral comprehension, which can be aggravated by the presence of hearing loss (1) .
Presbycusis is characterized by progressive hearing loss due to age, which can start at any point, but it is most expected after the age of 60.Traditionally, it is characterized as a bilateral hearing loss, especially for the higher frequencies; the results of the Speech Recognition Index (SRI) range widely, depending on the location of the lesion; recruitment may or may not be present; acoustic reflexes are absent, or present with recruitment (2) .
Hearing aids can be used to rehabilitate the elderly patient with hearing loss, but despite amplifying and modifying the acoustic stimuli according to each person's needs, and even though they enable the perception of environmental and speech sounds, they do not directly change the brain or the behavior of the user (3) .
Therefore, even though the audibility of a speech sound can be immediately restored after the adaptation of hearing aids, it takes some time for the user to learn how to interpret the acoustic information that has been recently introduced.So, training can be necessary in order to optimize the benefits of hearing aids, thus improving speech recognition skills (4) .
A study (5) suggested that to follow-up the patient only until the moment of hearing aid acquisition is not enough, and reported how important it is for the patient to feel cared for and to have good interaction with the speech-language therapist.Besides, as observed in another research (6) , counseling sessions improve the subject's self-assurance and confidence on how to maintain good communication skills, as well as how to handle and care for the hearing aids.
The standard auditory training for the elderly is possible; however, tasks that involve difficult hearing conditions can cause frustration, discouragement and even rejection of the training process, leading to the consequent abandonment of the hearing aid.Therefore, the objective of this study was to develop an auditory training that could be more interesting, ludic and joyful for the elderly wearing hearing aids, which was the Music Auditory Training (MAT) (7) .The author aimed to offer challenging stimuli in repeated motivating tasks The researcher assessed changes on the subject's communication skills resulting from auditory stimulation.This study used the test known as SSW (Staggered Spondaic Word Test) (8) , adapted to Portuguese (9) , which evaluated different skills with the dichotic hearing task.
Therefore, this study aimed to verify the effects of auditory rehabilitation by analyzing quantitative and qualitative aspects of the SSW test in elderly people who have recently started wearing hearing aids.Those who met the pre-established criteria were informed about the study, and received information such as: objectives, procedures, foreseen risks and benefits, and secrecy concerning identification.Out of these, the ones who accepted to participate voluntarily signed the Informed Consent Form.

This
Participants should meet the pre-established inclusion criteria: • Being older than 60 years, age from which the person is considered as an elderly person in developing countries, according to the World Health Organization (WHO); • Having bilateral symmetrical sensorineural hearing loss, ranging from mild to moderately severe (10) (11) at the Mini-mental State Examination (MMSE) (12) .This examination is used as screening in order to identify possible changes in specific cognition functions, such as: orientation, memory, attention, language and visual constructive capacity, and it is frequently used in hospitals and clinics.Therefore, in order to enable the execution of the research, especially considering that the subjects should attend the service for at least nine consecutive weeks, patients from other cities were referred to compose the group that did not undergo auditory rehabilitation (G1), while those living in Santa Maria were preferentially placed in the group submitted to auditory rehabilitation (G2).However, auditory rehabilitation was also available for subjects in G1, but only after the final assessment.
Thus, the study had the participation of two distinct groups, G1 and G2.Both groups started the research procedures after the partial discharge of the Concession Program of Hearing Aids, which occurs after the patient has adapted and returned for at least one appointment, presenting no more doubts or complaints.In the appointment for the adaptation of hearing aids, patients are informed about the use, care and handling of the devices.
G1 was comprised by eight subjects (three females and five males), aged between 66 and 81 years, who wore the hearing aids for seven weeks.G2 was comprised by nine subjects (three females and six males), aged between 60 and 84 years, who underwent an auditory rehabilitation program structured into seven sessions, each one lasting one hour and 15 minutes.These sessions took place once a week, with the presence and the supervision of the responsible researcher.
All subjects were submitted to the Staggered Spondaic Word Test (SSW) at two different assessment moments: at the beginning and at the end of the study.G2 was assessed before and after auditory rehabilitation, and G1 was also evaluated with the same interval between assessments.SSW (8) was adapted to Portuguese (9) , and it consists of the dichotic presentation of 40 items containing two pairs of "dissyllable paroxytone words".
At the application of the test, a word is presented to an ear without competition and then two words simultaneously; finally, one word is presented to the other ear without competition.Half of the items begin on the right ear (RE), and the other half, on the left ear (LE), alternately.The omission, substitution or distortion of a word is considered a mistake.The addition or the omission of a phoneme, as well as the slow response, is not considered as errors (even though they should be qualitatively observed).
In our study, quantitative aspects were considered: noncompetitive right (NCR), competitive right (CR), competitive left (CL), non-competitive left (NCL) and total of hits.Qualitative aspects were: order effect (OE), auditory effect (AE), inversions and Type A. The errors for qualitative aspects are used to categorize possible deficits.Changes in order and auditory effects, may suggest deficits in phonemic decoding (PD) or indicate gradual memory loss (GML).The presence of one or more inversions indicates organization deficit (Org), and the presence of Type A pattern, integration deficit (Int) (13) .
For the application of SSW, at first the proper calibration of the equipment was performed with the pure tone available in the first track of the compact disk (CD), and the VU meter was set to the zero position.Afterwards, stimuli were presented in an average of 30 dB NS, considering the acoustic comfort for each subject under evaluation.It is worth to mention that the intensity used in the final evaluation was similar to the one used in the initial evaluation.
Measures were obtained in an acoustically treated room with a two channel digital audiometer, Fonix ® , model FA-12, type I and type TDH-39 P ear phones, Telephonics ® .Stimuli were presented by the CD inserted in a digital CD player, Toshiba ® , model 4149, attached to the audiometer.
The auditory rehabilitation program consisted of hearing counseling to the participants and the auditory training itself, according to the schedule specified ahead.
Concerning hearing counseling, the objectives of the tasks developed were approached in each session, as well as their application in daily communication situations.Communication strategies were provided, and the practical aspects of wearing hearing aids were reinforced.
In order to conduct the auditory training, music auditory training (MAT) (7) was used.It is comprised of seven DVDs, which contemplate temporal processing hearing skills (temporal resolution and order) and selective attention by means of auditory training exercises related to figure-background of instrumental sounds, frequency and duration of sounds, directed listening, rhythm, and auditory closure.Besides the mentioned hearing skills, each exercise involves attention and work memory.
Besides, the subjects were encouraged to weekly report the differences, difficulties and facilities noticed during training with hearing aids.On the other hand, the goal was to reinforce the positive aspects of the patients' performance, encouraging them to overcome their difficulties in the next session, aiming to optimize speech comprehension, to maintain the quality of the dialogue, to develop confidence in social interaction, and to be able to handle and care for their hearing aids.
The presentation of the aforementioned material was conducted by means of a computer with a DVD reader, to which were attached two sound boxes with mini subwoofer 2.1, by Clone ® , model 11128 and 5 w potency (RMS), placed in a quiet room one meter away from the patient.One of them was placed to the right and the other to the left of the computer, resulting in an azimuth of 45º in relation to the subject.
Before starting the hearing training sessions, hearing aids were verified as to functioning, thus ensuring the audibility of sounds, and new batteries were used in all sessions.
Thus, data collection lasted nine weeks for each participant, excluding absences and holidays.The first and last weeks were destined to assessments, and the others addressed auditory rehabilitation.The auditory rehabilitation program was organized as follows: • Session 1: Initial assessment; • Session 2: Verification and orientation as to placement and removal aspects of hearing aids (including ear molds or thin tubes and oliva, in cases of open adaptation), use of cases and application of the background DVD about instrumental sounds; • Session 3: Verification and instructions as to aspects related to volume control and/or program button and application of the background DVD about sequential sounds; • Session 4: Verification and instructions about aspects related to the batteries in hearing aids and the application of the DVD regarding duration of sounds; • Session 5: Verification and instructions about aspects related to cleaning ear molds or thin tube and oliva, and the application of the DVD regarding frequency of sounds; • Session 6: Verification and instructions about aspects related to the use of a telephone with hearing aids (exploring adjustments for this purpose) and application of the DVD regarding rhythm temporal structure; • Session 7: Verification and instructions about aspects related to the use of dehumidifiers and the application of the DVD regarding auditory closure; • Session 8: Application of the DVD Directed Listening, and as to practical aspects, there was a session for doubts, with items suggested by each subject or issues about which there was the need for reorientation;

• Session 9: Final Assessment
The statistical analysis of data was performed with the software Statistica 9.0.In order to analyze the behavior of quantitative variables, the Lilliefors test was employed.Therefore, for the variables that had an approximately normal distribution, parametric tests were used, as well as the Student's t-test for two dependent samples when analyzing the performance of each group in the initial and the final assessment, and also the Student's t-test for both independent samples to analyze the performance of both groups in each moment: the beginning and the end.
Concerning those that did not have an approximately normal distribution, non-parametric tests were used, as well as the Wilcoxon test and the Mann-Whitney U test, respectively.In order to analyze the composition of groups as to gender, the Fisher's Exact test was used.The result was considered as significant when p≤0,05, i.e, a significance level of 5% (14) .

RESULTS
No differences were observed as to the gender of subjects in both groups (p=10), nor concerning their age (p=0.827).
Table 1 exposes the descriptive measures of quantitative aspects from the SSW test, both for G1 and G2, in the initial and final assessments, as well as the analysis of results.Table 2 shows the descriptive measures of the quantitative aspects and the analysis of results obtained for both groups in the final evaluation.
It is possible to observe that only the group submitted to auditory training presented differences between the initial and final assessments (Table 1).
Table 2 shows that, at the final assessment, subjects from G2 presented better results in comparison to those in G1.
Table 3 presents the categorizations of deficits for all subjects in both groups, at the initial and final assessments, according to qualitative measures from the SSW test.
Table 4 shows the percentage of deficit in initial and final assessments in each group.

DISCUSSION
According to the previously described objectives, this study analyzed both the quantitative and qualitative aspects   A statistical analysis of the results was performed for the quantitative aspects in order to check the differences between the initial and the final assessments for each studied group (Table 1).Even though no significant differences were found between the results of G1, both groups improved in all quantitative aspects considered in this study.These data show how important it is to adjust the hearing aids of elderly patients with hearing impairment, but they also show how the performance of these patients can be even better when there is auditory rehabilitation associated with the hearing aid.
Only the subjects in G2 presented significant improvement between evaluations, considering the variables CR, NCL and total of hits.The assessment conditions CR and NCL present a characteristic in common to assess the left hemisphere (LH).So, the significant improvement between the initial and final results obtained for G2 shows the satisfactory effect of auditory training, considering that LF is involved with rhythms, semantic identification of melodies, sense of familiarity, temporal and sequence processing of sounds (15) .All of these aspects were stimulated in the auditory training program conducted in this study by means of MAT (7) .
In this context, considering that the LH concentrates the structures involved in the perception of acoustic cues for speech, such as frequency, intensity and duration (16) , it is possible to say that those submitted to auditory training benefited from the intervention, since they presented more satisfactory results in the final assessment of the variables that analyze this hemisphere.
The significant improvement observed in the performance of subjects in G2 only for the CR and NCL variables, and not CoDAS 2013;25(2):169-75 at first reaches the right hemisphere (RH), and only then is transmitted to the LH for analysis and interpretation (16) .This asymmetry can be justified by the progressive deterioration of the corpus callosum due to aging, which leads to the decreasing efficiency of interhemispheric transfer (17) .
When comparing the values obtained for the quantitative aspects in the final assessment for both groups, it is observed that subjects in G2 presented a more satisfactory performance in relation to G1 for the variables NCR, LC, NCL and total of hits (Table 2), confirming the importance of performing the auditory training, since both groups underwent the adaptation and use of hearing aids for the same period of time and the intervention was the differential aspect between groups.
A study assessing children by means of auditory evoked potentials demonstrates the importance of music-related activities to improve left hemisphere functions (18) .The authors found essential changes in the LH of children who only had one year of violin practice compared to those with no practice at all.
Auditory training can be considered as a facilitating agent for speech recognition because it represents specific hearing experiences which exercise and try to improve hearing skills.Besides, it is known that it can improve the perception of complex acoustic stimuli, such as speech, and that one of its basic features is the plasticity of the central auditory nervous system (19) .
In this context, studies (20,21) which aimed to verify the efficiency of auditory training with elderly people wearing hearing aids concluded that the training, associated with the use of hearing aids, improves the performance of speech recognition skills and reduces the restricted participation of this population.
As to the qualitative aspects of the SSW test, in both groups it was possible to observe that some participants maintained their performance, others improved it and some even decreased it (Tables 3 and 4).These differences and inconsistency of answers is in accordance with another study (22) , in which the authors report great variability of the results found in the analyses of assessment of elderly individuals.
Generally, there were several differences in this study, which may be due to the reduced sample size.However, another study (1) also found many changes in the assessment of the elderly with the SSW test, and suggested that regardless of hearing loss, the age factor plays an important role in the unsatisfactory performance.

CONCLUSION
Both studied groups presented improvement for all the quantitative aspects of the SSW test, which shows the importance of adapting hearing aids for elderly with hearing impairment.
The scores reached by the subjects in the group submitted to auditory rehabilitation in the variables of competitive right, non-competitive left and total of hits demonstrate the improvement provided by auditory training concerning the functioning of the left hemisphere.
There is great variability of results, observed by means of the assessments concerning the qualitative aspects of the elderly individuals' performance.To gather evidence of the differences between these results, a reassessment would possibly be needed after a longer period of time to verify if there would really be changes in auditory perceptions that could be associated with other sensory functions.
* AHL and TRH were responsible for the research; MJC and AGR were responsible for orientation.
is a descriptive, longitudinal, quantitative and experimental study conducted at Núcleo de Seleção e Adaptação de Próteses Auditivas (NUSEAPA), of the Speech-Language Pathology Center of Universidade Federal de Santa Maria (UFSM).Data were collected from March to December 2010, connected to the research project entitled "Pesquisa e Base de Dados em Saúde Auditiva" (Research and Data Base in Auditory Health"), registered in the Project Center Health Sciences office with number 019731, approved by the Research Ethics Committee of UFSM, with number 0138.0.243.000-06, on December 5, 2006.Medical records of patients who were waiting for hearing aids at NUSEAPA, by means of the Concession Program of Hearing Aids by the secretariat of health care -Ministry of Health, were analyzed for the selection of participants It is worth to mention that the elderly who wear hearing aids came from the Concession Program of hearing aids, which contemplates the 4 th State Health Department and involves the cities of Santa Maria and those in the west central region in the state of Rio Grande do Sul (Brazil).Elderly people after auditory rehabilitation

Table 1 .
Descriptive measures of the quantitative aspects of the Staggered Spondaic Word Test of both groups, at the initial and final assessments *Significant values (≤0.05) -Student's t test for two dependent samples or Wilcoxon test according to the distribution of variables.Legends: G1 = group not submitted to auditory training; G2 = group submitted to auditory training; As1 = initial assessment; As2 = final assessment; NCR = non competitive right; CR = competitive right; NCL = non competitive left; CL = competitive left Elderly people after auditory rehabilitation CoDAS 2013;25(2):169-75

Table 3 .
Categorization of deficits presented by subject, in initial and final assessments, from the qualitative aspects of the Staggered Spondaic Word Test for NCR and CL, agrees with another study which reports that the acoustic information received by the right ear in a dichotic task and processed in the LH is frequently better analyzed and organized than the information received by the left ear, which

Table 2 .
Descriptive measures of the quantitative aspects of the Staggered Spondaic Word Test of both groups, at the final assessment

Table 4 .
Categorization of deficits presented by the subjects in both groups at the initial and final assessments, from the qualitative aspects of the Staggered Spondaic Word Test of the SSW test in two groups of elderly people who have recently started to wear hearing aids.One of the groups was submitted to an auditory rehabilitation program (G2), and the other did not go through the same program, and only wore the hearing aids (G1).