Influence of the degree of hearing impairment on central auditory processing in people with presbycusis

Abstract

Background

Auditory processing involves decoding auditory impulses along auditory pathways in the central nervous system. Aging causes a decline in hearing and auditory processing abilities. Difficulties in auditory information processing include limitations in transferring, processing, organizing, transforming, analyzing, storing, recalling, and using auditory information. The aim of this research was to examine the influence of hearing impairment on auditory processing abilities in people with presbycusis. In addition, this research aimed to determine whether gender and age affect auditory processing in people with presbycusis.

Method

The research included 43 participants, 59–90 years of age. The PSP-1 Auditory Processing Disorder Test Battery was used to examine auditory processing abilities. We also used liminal tonal audiometry and the Short Portable Mental Status Questionnaire–SPMSQ.

Results

The participants achieved the worst results on the speech-in-noise test and the dichotic word test. A statistically significant difference was found in auditory processing abilities with regard to age (p < 0.001) and the degree of hearing impairment (p < 0.001). No statistically significant differences were determined in relation to gender. Regression analysis pointed out the degree of hearing impairment as a significant predictor of auditory processing abilities (p < 0.001).

Conclusion

Auditory processing abilities decline with age, and the degree of hearing impairment significantly affects these abilities.

Background

Aging is a natural process involving a decline in both physical and mental abilities [1]. Aging-related physiological changes have been found in peripheral and central auditory systems [2]. Hearing loss, often present in older people, is a complex challenge with numerous social, medical, and societal implications, which indicates the significance of a comprehensive analysis of the hearing loss problem in the elderly population [3].

Progressive hearing loss that occurs with aging due to neurodegenerative processes in peripheral and central parts of the auditory system is called presbycusis [4]. This type of hearing loss most commonly occurs after the age of 60 [5] in the form of gradual, bilateral, and symmetrical sensorineural hearing loss [6]. Presbycusis primarily involves an increase in high-frequency auditory thresholds (from 4 to 8 kHz) [4], reduced speech comprehension in a noisy environment, and slower acoustic information processing [7]. Two-thirds of people over the age of 70 have hearing loss caused by aging [8], increasing to over 80% after the age of 85 [9]. Some studies state that high-frequency hearing loss (8 kHz) already occurs in the 40 s [10]. Research points out that, apart from hearing loss, aging also causes difficulties in auditory information processing [11, 12].

Auditory processing can be defined as decoding an auditory stimulus along auditory pathways in the central nervous system [13]. Auditory processing disorder refers to people with typical hearing who face challenges in receptive communication and/or language difficulties caused by problems in auditory information processing in the central nervous system [14]. According to most definitions, auditory processing disorder is characterized by typical hearing, a neurological basis of the disorder, impaired listening ability, and difficulties in receiving, understanding, and using auditory information [15]. Lin et al. [8] state that the prevalence of auditory processing disorder in people over 85 exceeds 65% in the USA.

Aging-related auditory processing difficulties are most commonly detected on speech-in-noise and dichotic tests [16]. As the corpus callosum atrophies with age, the dichotic listening ability decreases. Also, maintaining attention during dichotic listening becomes more and more challenging with age [17], as well as the ability to accurately and quickly process subtle differences between stimuli, which helps to understand speech in challenging auditory situations (while listening to fast speech and incomplete speech signals) [16, 17]. In addition to dichotic listening difficulties, aging-related auditory processing disorder also involves poorer speech comprehension in a noisy environment and/or in the presence of a competing speech signal [18]. Older people with auditory processing difficulties often have problems with talking over the phone, following a conversation, especially when it includes several people, and following and understanding fast speech [17, 19].

Due to a lack of support and adequate information, a decline in hearing abilities can often go unnoticed or be interpreted as a physiological aging process [20]. Hearing loss and auditory processing difficulties, accompanied by hindered speech comprehension, may negatively affect the quality of life and mental health [21]. A better understanding of this problem can contribute to improving diagnostic and therapeutic methods and influence environmental adjustment in order to facilitate communication and provide adequate support.

The aim of this research was to examine the influence of the degree of hearing impairment on auditory processing abilities in people with presbycusis. In addition, this research aimed to determine whether gender and age affect auditory processing abilities in people with presbycusis.

Methods

Sample

The sample included 43 participants 59–90 years of age (M = 79.02, SD = 8.84), selected by convenience sampling. Inclusion criteria involved the following: aging-related hearing impairment, absence of acute and chronic middle ear infections, absence of acute and chronic central nervous system diseases, good mental and cognitive status, and not using medications that can affect the central nervous system. All participants underwent a comprehensive audiological evaluation prior to the study, confirming that they had healthy middle ears. There were 33 women (76.7%) and 10 men (23.3%) in the sample. The participants were divided into three groups with regard to the degree of hearing impairment: the first group included 19 participants with mild hearing impairment (44.2%), the second group included 19 participants with moderate hearing impairment (44.2%), and the third group included five participants with moderate-severe hearing impairment (11.6%). The participants did not use hearing aids during research. Regarding age, the participants were divided into two groups: the younger group consisting of ten participants (23.3%) and the older group consisting of 33 participants (76.7%). The results of the χ² test showed that the sample was not uniform with regard to gender (p < 0.001) and age (p < 0.001). Also, the results of the χ² test showed that regarding the degree of hearing impairment, the sample was uniform with regard to gender (p = 0.69) but not with regard to age (p = 0.004).

Ethics approval and consent to participate

Participation in this study was voluntary, and participants were informed they could withdraw at any time. All participants provided signed, informed consent prior to taking part in the study. No personal information or identifying data was collected, and no invasive procedures were performed. The Ethics Committee of the Institute of Experimental Phonetics and Speech Pathology approved the study protocol (No. O-23–02). This research was supported by the Ministry of Science, Technological Development, and Innovation of the Republic of Serbia (Contract No. 451–03-65/2024–03/200096).

Data collection techniques

All participants in this research underwent liminal tonal audiometry. Based on the air conduction curve of the audiogram, we calculated the pure tone average–PTA as the mean value of the hearing threshold at four frequencies: 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz. The degree of hearing impairment was determined according to the PTA: mild hearing impairment from 26 to 40 dB, moderate hearing impairment from 41 to 55 dB, and moderate-severe hearing impairment from 56 to 70 dB. All participants had bilateral sensorineural hearing impairment.

The Short Portable Mental Status Questionnaire–SPMSQ [22] was used in this research. The questionnaire includes ten questions and is used to examine cognitive deficits in older people. With regard to the number of incorrect answers, the test achievement can be classified into four categories: normal mental functioning (0–2 mistakes), mild cognitive impairment (3–4 mistakes), moderate cognitive impairment (5–7 mistakes), and severe cognitive impairment (8 and more mistakes). In the described research, this questionnaire was used as a control one to check the participants’ mental status. Participants whose results belonged to the category of normal mental functioning took part in further research.

The PSP-1 Auditory Processing Disorder Test Battery [23] was used to examine auditory processing abilities. The PSP-1 test is primarily intended and standardized for examining auditory processing abilities in children from 5.5 to 11.5 years of age and is also used to detect auditory processing disorders in adults. The PSP-1 test battery includes four subtests: filtered words test, speech-in-noise test, dichotic word test, and dichotic sentence test. The test was administered in the participants' native language. Sound presentation levels were set at their most comfortable loudness level (MCL).

The filtered words test is a monaural low-redundancy speech test that examines the ability to recognize words with reduced intelligibility. This test includes two lists of 17 monosyllabic words, balanced regarding frequency and phonology for the left and right ear. Left and right-ear words include an equal number of sounds with regard to the manner and place of articulation and are uniform according to the frequency spectrum.

Like the filtered words test, the speech-in-noise test is also a monaural low-redundancy speech test that examines the ability to understand speech in challenging listening conditions. The test includes two lists of 14 monosyllabic words for each ear, which are phonologically balanced and equally used in everyday speech. The words were presented with the background noise of a completely unintelligible continuous murmur of a large number of people, with a uniform intensity that was 8 dB lower than the intensity of the word stimulus.

The dichotic word test is a binaural word test comprising 30 pairs of words (15 pairs for each ear, i.e., 60 words in total) simultaneously presented to both ears. The duration of the stimulus in both ears is equal and lasts for 1 ms. The participants are asked to repeat both words by repeating the word they heard in the right ear in the first part of the test and then the word they heard in the left ear in the second part of the test.

The dichotic sentence test is a binaural test, also called the competency or binaural separation test. During this test, two different sentences are simultaneously presented to both ears, and the participants have to repeat the sentence they heard in one ear (first the right ear and then the left ear in the second part of the test) while ignoring the auditory stimulus in the other ear. The test includes ten pairs of sentences for each ear, which are equal regarding duration and beginning of presentation.

The results of the tests are obtained by adding up the correct answers, i.e., correctly repeated words or sentences. The total PSP-1 score is the sum of all correct answers on the tests. The maximum score on the filtered words test is 34, 28 on the speech-in-noise test, 60 on the dichotic word test, and 20 on the dichotic sentence test. The maximum total PSP-1 score is 142. The average test duration is about 25 min.

Statistical analysis

All statistical analyses were performed using the IBM SPSS Statistics for Windows, version 20.0. The analysis included all 43 participants, with no missing data. Descriptive statistical measures used included counting measures (frequency and percentage), measures of central tendency (mean and median), and measures of variability (standard deviation and interquartile range). Statistical significance was set at a threshold of p < 0.05. Values of p < 0.01 were considered highly significant, while p < 0.001 indicated very high statistical significance. Values of p > 0.05 were considered not statistically significant.

Results

The results of the Kolmogorov–Smirnov test show no deviations from the normal distribution in the total PSP-1 score on the dichotic word test and the speech-in-noise test (p > 0.05). Deviation from the normal distribution was found only in the scores of the filtered word test and the dichotic sentence test at the significance level of p < 0.05. Since there was no deviation from the normal distribution for most subtests and the PSP-1 test in total, Pearson correlation, t-test, and analysis of variance were used in further data analysis. Additionally, regression analyses were conducted to explore the joint influence of predictor variables on overall PSP-1 scores and individual subtest performances.

Table 1 shows descriptive statistics of the PSP-1 total scores. The participants achieved the best average score on the dichotic sentence test, which was 12.51 out of the maximum 20 points (62.55%). The participants’ average score on the filtered words test was 17.26 out of the maximum 34 points (50.76%). The participants achieved lower average scores on the speech-in-noise and the dichotic word tests. The average score on the speech-in-noise test was 13.14 out of the maximum 28 points (46.93%), while the average participants’ score on the dichotic word test was 26.40 out of the maximum 60 points (44.00%). The overall results of the PSP-1 test indicate that the average score on the complete test was 69.30 out of the maximum 142 points (48.80%). The lowest score was 0, and the highest was 122, with a standard deviation of 33.78.

Table 1. Descriptive statistics of the PSP-1 total scores

Test	M	Mdn	SD	Min	Max	SE
Filtered words test	17.26	21.00	8.83	0	29	1.35
Speech-in-noise test	13.14	14.00	6.03	0	23	0.92
Dichotic word test	26.40	25.00	15.16	2	52	2.30
Dichotic sentence test	12.51	12.00	6.45	0	20	0.98
PSP-1 overall	69.30	71.00	33.78	4	122	5.15

Note: PSP-1 overall the sum of the results of all tests

Results achieved on PSP-1 in relation to the degree of participants’ hearing impairment

Table 2 shows descriptive statistics of the results achieved on PSP-1 in relation to the degree of hearing impairment. The participants with mild hearing impairment achieved the highest average scores on all subtests of the PSP-1 battery, while the participants with moderate-severe hearing impairment had the lowest average scores. The average total score on PSP-1 of the participants with mild hearing impairment was 98.63 points. The participants with moderate hearing impairment achieved an average of 52.53 points, while those with moderate-severe hearing impairment achieved an average of 21.60 points.

Table 2. Descriptive statistics of the overall PSP-1 scores in relation to the degree of hearing impairment

Test	Degree of hearing impairment	M	Mdn	SD	Min	Max	SE
Filtered words test	Mild	23.79	25.00	3.55	14	29	0.81
	Moderate	14.21	13.00	7.85	3	26	1.80
	Moderate-severe	4.00	4.00	4.24	0	10	1.90
Speech-in-noise test	Mild	18.05	19.00	3.03	12	23	0.69
	Moderate	10.37	11.00	4.40	0	18	1.01
	Moderate-severe	5.00	2.00	4.47	2	12	2.00
Dichotic word test	Mild	39.05	41.00	10.35	18	52	2.37
	Moderate	18.21	19.00	9.59	3	41	2.20
	Moderate-severe	9.40	4.00	8.82	2	20	3.94
Dichotic sentence test	Mild	17.74	19.00	3.36	9	20	0.77
	Moderate	9.74	9.00	4.81	2	20	1.10
	Moderate-severe	3.20	2.00	2.68	0	6	1.20
PSP-1 overall	Mild	98.63	103.00	17.35	65	122	3.98
	Moderate	52.53	52.03	20.95	10	104	4.81
	Moderate-severe	21.60	11.00	19.63	4	48	8.78

One-factor analysis of variance determined a statistically significant difference in the scores of all subtests and the overall PSP-1 scores in relation to the degree of participants’ hearing impairment (p < 0.001).

Sheffe’s pairwise comparison test showed a statistically significant difference between groups of participants with different degrees of hearing impairment in the scores achieved on individual subtests and the overall PSP-1 scores. A statistically significant difference was not determined only between the scores of the participants with moderate and moderate-severe hearing impairment on the dichotic word test (p > 0.05) (Table 3).

Table 3. The results of Sheffe’s pairwise comparison test on PSP-1in relation to the degree of hearing impairment

Hearing impairment		Filtered words test	Speech-in-noise test	Dichotic word test	Dichotic sentence test	PSP-1 overall
In relation to the degree		p	p	p	p	p
Mild	Moderate	0.000	0.000	0.000	0.000	0.000
Mild	Moderate-severe	0.000	0.000	0.000	0.000	0.000
Moderate	Moderate-severe	0.001	0.001	0.261	0.040	0.005

Results achieved on PSP-1 in relation to participants’ gender

Table 4 indicates that women had better average scores on the overall PSP-1 test and all subtests except the speech-in-noise test. Women achieved an average score of 71.84 points on PSP-1, while men’s average score was 61.91.

Table 4. Descriptive statistics of the overall PSP-1 scores in relation to gender

	Gender	M	Mdn	SD	Min	Max	SE
Filtered words test	Women	17.50	21.50	9.11	0	29	1.61
	Men	16.55	21.00	8.32	4	27	2.51
Speech-in-noise test	Women	13.13	14.50	6.43	0	23	1.14
	Men	13.18	12.00	4.96	2	20	1.49
Dichotic word test	Women	27.91	26.50	15.75	2	52	2.78
	Men	22.00	20.00	12.83	3	44	3.91
Dichotic sentence test	Women	13.31	14.50	6.46	0	20	1.14
	Men	10.18	9.00	6.10	2	20	1.84
PSP-1 overall	Women	71.84	72.00	35.09	4	122	6.20
	Men	61.91	53.00	29.93	11	104	9.02

Note: PSP-1 overall the sum of the results of all tests

The Student t-test showed no statistically significant difference in the scores of individual subtests or in the overall PSP-1 score in relation to the participants’ gender (p > 0.05).

Results achieved on PSP-1 in relation to participants’ age

Participants in the younger group had better average scores on all subtests and the overall PSP-1 test. The average score of younger participants on PSP-1 was 95.90 points, while the average PSP-1 score of the participants in the older group was 61.21 points (Table 5).

Table 5. Descriptive statistics of the overall PSP-1 scores in relation to age

	Age	M	Mdn	SD	Min	Max	SE
Filtered words test	Younger group	24.10	23.50	3.45	20	29	1.09
	Older group	15.15	14.00	8.90	0	27	1.55
Speech-in-noise test	Younger group	17.20	19.00	4.02	11	22	1.27
	Older group	11.94	12.00	6.07	0	23	1.06
Dichotic word test	Younger group	37.20	39.00	12.51	13	51	3.96
	Older group	23.12	22.00	14.50	2	52	2.52
Dichotic sentence test	Younger group	14.72	18.50	3.75	8	20	1.18
	Older group	11.00	10.00	6.35	0	20	1.11
PSP-1 overall	Younger group	95.90	97.00	21.10	53	120	6.67
	Older group	61.21	55.00	32.89	4	122	5.72

Note: PSP-1 overall the sum of the results of all tests

The Student t-test determined a statistically significant difference in the scores of individual subtests and the overall PSP-1 test in relation to participants’ age. The difference in scores with regard to participants’ age was statistically significant at p = 0.01 on the speech-in-noise test, dichotic word test, and the overall PSP-1, while the statistical significance at p < 0.001 was determined for the filtered words and dichotic sentence tests.

A comparison between age groups indicated that younger participants generally achieved higher PSP-1 scores. It was important to investigate how age, combined with factors like hearing impairment and gender, affected performance across all subtests. Such an analysis provided a more comprehensive understanding of the factors contributing to individual variability in auditory processing outcomes.

Pearson correlation showed a statistically significant correlation between the overall PSP-1 scores, as well as the scores of all subtests, with the degree of hearing impairment (p < 0.001) and participants’ age (p < 0.001). The direction of the correlation is negative, indicating that younger participants and those with milder hearing impairment achieved higher scores on the PSP-1 test. There was no statistically significant correlation between participants’ gender and PSP-1 scores (Table 6).

Table 6. Correlation of the degree of hearing impairment, age, and gender with the PSP-1 scores

	Degree of hearing impairment	Age	Gender	Filtered words test	Speech-in-noise test	Dichotic word test	Dichotic sentence test
Degree of hearing impairment
Age	0.470**
Gender	− 0.021	0.088
Filtered words test	− 0.786**	− 0.434**	− 0.023
Speech-in-noise test	− 0.814**	− 0.372*	− 0.031	0.875**
Dichotic words test	− 0.746**	− 0.397**	0.106	0.716**	0.813**
Dichotic sentence test	− 0.769**	− 0.426**	0.164	0.772**	0.799**	0.879**
PSP-1 overall	− 0.833**	− 0.439**	0.067	0.886**	0.925**	0.949**	0.930**

Note: **p < 0.001

Due to a strong correlation between the criterion variable and the degree of hearing impairment and age as predictor variables, and because of a strong intercorrelation between these predictor variables, we performed additional verification to eliminate the suppressor effects. Statistical collinearity analysis showed that the tolerance coefficients for all predictor variables were greater than 0.10 and that variance inflation factors were below 10. These results indicate that none of the predictor variables was redundant.

A regression analysis was performed to determine the joint influence of the degree of hearing impairment, age, and gender on the overall scores of the PSP-1 auditory processing test. The coefficient of multiple determination showed that 68% of the variance of participants’ achievement in the overall PSP-1 scores can be explained by individual differences in the predictor variables. Out of the three predictor variables, only the degree of hearing impairment was distinguished as an independent predictor of achievements on all subtests and the overall PSP-1 (p < 0.001) (Table 7).

Table 7. Regression analysis of the degree of hearing impairment, age, and gender in relation to PSP-1 scores

Predictors	Filtered words test
	R2	F(p)	β(p)
Degree of hearing impairment	0.595	21.556 (0.000)	− 0.749 (0.000)
Age			− 0.079 (0.483)
Gender			− 0.032 (0.748)
Predictors	Speech-in-noise test
	R2	F(p)	β(p)
Degree of hearing impairment	0.640	25.901 (0.000)	− 0.825 (0.000)
Age			0.021 (0.847)
Gender			-0.050 (0.593)
Predictors	Dichotic word test
	R2	F(p)	β(p)
Degree of hearing impairment	0.536	17.186 (0.000)	− 0.711 (.0.000)
Age			− 0.071 (0.556)
Gender			0.098 (0.361)
Predictors	Dichotic sentence test
	R2	F(p)	β(p)
Degree of hearing impairment	0.592	21.335 (0.000)	− 0.718 (0.000)
Age			− 0.102 (0.368)
Gender			0.158 (0.120)
Predictors	PSP-1 overall
	R2	F(p)	β(p)
Degree of hearing impairment	0.676	30.229 (0.000)	− 0.799 (0.000)
Age			− 0.068 (0.499)
Gender			0.057 (0.526)

We also analyzed the individual contribution of each variable using stepwise regression, which confirmed that only the degree of hearing impairment had a significant individual contribution to the PSP-1 scores. About 69% of the PSP-1 score variability can be explained by individual differences in the degree of hearing impairment. Participants’ age and gender did not significantly influence the PSP-1 scores (Table 8).

Table 8. Results of semi-partial correlations: the degree of hearing impairment, age, and gender in relation to the PSP-1 scores

Predictors	Filtered words test		Speech-in-noise test		Dichotic word test		Dichotic sentence test		PSP-1 overall
	R2	R2 change (p)	R2	R2 change (p)	R2	R2 change (p)	R2	R2 change (p)	R2	R2 change (p)
Degree of hearing impairment	0.693	0.693 (0.000)	0.617	0.617 (0.000)	0.663	0.663 (0.000)	0.546	0.557 (0.000)	0.693	0.693 (0.000)
Age	0.696	0.003 (0.538)	0.623	0.623 (0.454)	0.663	0.000 (0.892)	0.538	0.003 (0.623)	0.696	0.003 (0.538)
Gender	0.699	0.003 (0.526)	0.624	0.624 (0.748)	0.666	0.002 (0.593)	0.536	0.009 (0.361)	0.699	0.003 (0.526)

Discussion

The PSP-1 auditory processing test results indicate that the participants achieved the lowest scores on the speech-in-noise subtest. These results are in accordance with several similar studies [24–26]. Adults with presbycusis commonly note speech comprehension difficulties in a noisy environment. One of the explanations for these difficulties in the elderly population is a decline in spatial sound processing abilities [27]. Spatial sound processing is defined as the ability to selectively pay attention to sounds coming from one direction while simultaneously suppressing the sounds from another direction [28]. A healthy cochlea, which will accurately receive and transmit IID (interaural intensity difference) and ITD (interaural time difference) signals, is needed to perform spatial sound processing smoothly. In presbycusis, the loss of outer hair cells, especially in the basal region of the cochlea, leads to reduced resolution of usually high frequencies [29]. If higher-than-normal excitation occurs in the cochlea, the ability to detect IID for each frequency decreases since the sound energy at one frequency will affect the over-excitation of nerve fibers compared to the expected one [27]. It should be emphasized that several research studies support the view that difficulties with speech comprehension in noise among older people are caused by poorer spatial sound processing [30, 31]. Glyde et al. [27] advise caution with such simplistic inferences, considering potentially confounding factors such as cognitive abilities and hearing impairment.

In our research, participants with presbycusis also achieved lower scores on the dichotic word test. Other studies had similar findings regarding dichotic word listening in the older population with presbycusis [32]. It is believed that dichotic listening impairment is one of the main symptoms of central auditory processing disorder in the elderly population, alongside presbycusis [33]. Dichotic listening impairment changes the linguistic information processing in the brain, which is especially pronounced in older people in challenging listening situations. Research shows that aging causes most changes to the central nervous system in the corpus callosum and upper temporal gyrus, i.e., their thickness decreases. Decreased gray matter density in the temporal gyrus and changes in the corpus callosum integrity lead to significant performance asymmetries in the ears of older people [34, 35]. Torrente et al. [36] showed that hearing impairment in people with presbycusis was related to listening in noise performance, while dichotic listening was related to cognition. They concluded that speech comprehension in people with presbycusis without hearing amplification was a complex process relying on hearing and cognition [36]. In their research, hearing and cognition were significant variables that explained 17% of the variability in the right ear and 27% in the left ear on the dichotic word test.

In the PSP-1 test results analysis, the degree of hearing impairment proved to be a significant predictor of auditory processing ability. Participants with milder hearing impairment had better scores on all subtests and the overall PSP-1 compared to both groups with more severe forms of hearing impairment. Participants with moderate hearing impairment achieved better results than those with moderate-severe hearing impairment. There was no statistically significant difference only between the participants with moderate and those with moderate-severe hearing impairment on the dichotic word test. Research by Torrente et al. [36], which included participants with mild and moderate hearing impairment, confirms that the achievement of the speech-in-noise test depends on the degree of hearing impairment. Similarly, Chinnaraj et al. [37] point out that mild and moderate hearing impairment significantly affects auditory processing abilities. Other authors also confirmed these findings in their research studies [38–40].

This research found a statistically significant correlation between the PSP-1 scores and the participants’ age. Regression analysis showed that age alone was not a significant predictor of the PSP-1 scores. However, in combination with the degree of hearing impairment, it significantly affected auditory processing abilities. Previous studies indicate that auditory processing abilities, especially speech comprehension in a noisy environment, decline with aging [41, 42]. Chinnaraj et al. [37] found a correlation between age and auditory processing ability. Young adults with typical hearing achieved significantly better results on auditory processing tests than older adults with typical hearing. Other studies also confirm that auditory processing abilities are related to aging [11, 12, 16, 43, 44].

The PSP-1 test showed no statistically significant differences in auditory processing abilities with regard to the gender of participants with presbycusis. Previous research on the influence of gender on auditory processing abilities in people with presbycusis is scarce. Souza Santos et al. [45] did not determine a statistically significant difference in auditory temporal processing abilities between men and women older than 60. Similar results were reported by Deperon et al. [46]. Research by Moor et al. [47] found that men under the age of 40 had poorer listening in noise skills compared to women. However, with aging, these skills gradually declined in women as well, and there were no differences in listening in noise skills in participants older than 60 with regard to gender.

One of the main limitations of this research is the sample size, which can reduce the possibility of generalizing the results. Furthermore, the participants were selected by convenience sampling, which may affect the sample representativeness. Another limitation may be using one testing battery that consists of only verbal stimuli and examines language-based auditory processing abilities, which may result in a lack of understanding of other aspects of auditory processing (temporal auditory processing, sound source localization). Also, we did not examine additional factors that may affect the PSP-1 test achievement, such as attention, working memory, and participants’ language skills. Despite the mentioned limitations, this research is significant since it presents the first use of the PSP-1 test in people with presbycusis and provides a significant insight into the auditory processing abilities of older people.

To achieve a comprehensive assessment, future research should include additional tests that use nonverbal stimuli to examine auditory processing abilities. Furthermore, future research could examine the effectiveness of different strategies for improving auditory processing abilities, such as hearing aids and auditory training.

Conclusion

The results of our research show that speech comprehension in a noisy environment and dichotic word listening are the greatest challenges for people with presbycusis. The degree of hearing impairment proved to be a significant predictor of auditory processing abilities in people with presbycusis. No statistically significant differences were found in PSP-1 scores with regard to the participants’ gender. Age alone was not a significant predictor of auditory processing abilities, while the coefficient of multiple determination (R² = 0.676) showed that, in combination with the degree of hearing impairment, they significantly affected auditory processing abilities. Understanding the factors that affect auditory processing abilities can help to develop better strategies for preserving and improving auditory functions in older people. Aging alone need not necessarily mean a decline in the quality of auditory functions, especially if hearing impairment and accompanying changes in communication and social interaction are adequately treated. This research emphasizes the importance of recognizing and understanding auditory processing difficulties, which are often neglected compared to hearing impairment, and which may significantly affect the mental health and quality of life of older people with presbycusis.

Acknowledgements

We would like to express our sincere gratitude to Prof. Mladen Heđever, the author of the PSP-1 Auditory Processing Disorder Test Battery, for his invaluable contribution to this study. His work on the development of the test has provided a critical tool for our research, and we are deeply appreciative of his support and guidance.

Authors’ contributions

All authors contributed significantly to the research and manuscript preparation. Marija Veletić (Lead Author) drafted the manuscript and made significant contributions to the study design and data collection. Sanja Đoković supervised the research project and provided overall guidance. Ljubica Isaković assisted with data interpretation and statistical analysis. Tamara Kovačević contributed to the conception and design of the study. Marija Bijelić critically revised the manuscript for important intellectual content. All authors read and approved the final manuscript.

Funding

This work was supported by the Ministry of Science, Technological Development, and Innovation of the Republic of Serbia (Contract No. 451–03-65/2024–03/200096).

Data availability

The datasets used and analyzed during the current study are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

Participation in this study was voluntary. Participants were aware that they could withdraw from the study at any time. All participants gave their signed, informed consent. No personal information or other identifying data was collected, nor were any invasive examinations performed. The ethics committee of the Institute of Experimental Phonetics and Speech Pathology approved the study protocol (No. O-23–02).

Consent for publication

All authors have read and approved the final manuscript and consent to its publication in The Egyptian Journal of Otolaryngology. Consent from participants for Publication Not applicable. This study does not contain any individual person’s data in any form (including individual details, images, or videos). All data used in this study are anonymous.

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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