Hye Yoon Seol

Background and Objectives This study aimed to explore speech performance using virtual reality (VR), comparing hearing aid (HA) and non-HA users, and to investigate the relationship between VR and conventional testing methods.Materials and Method Eighteen non-HA users and 13 HA users were enrolled in the study and completed puretone audiometry and speech testing in both quiet and noise. The conventional speech test was conducted in auditory only (AO). The multimodal testing conditions included AO, visual only (VO), and audiovisual (AV). Video recordings of a speaker saying test sentences at a café were displayed on a monitor (VO) and a VR headset (AV). Participants performed a sentence repetition task in AO, VO, and AV and percent-correct scores were obtained. All participants completed a questionnaire on listening abilities in diverse situations.Results A significant main effect of modality was observed, with the highest speech performance for the non-HA users, followed by HA users in the aided and unaided conditions. Post-hoc comparisons showed a significant difference between AO and VO conditions. No significant correlations were found between questionnaire results and multimodal speech performance in either quiet or noise.Conclusion The addition of visual information is helpful for communication for those with HL regardless of HA use and the presence of noise, and multisensory integration may play a more critical role in certain situations depending on the characteristics of HL. There is a potential for multimodal testing to be employed into clinical practice, but ample work is still needed to further validate the test method.

Hearing loss (HL) affects the quality of life, with significant impacts on health, communication, social, and emotional interactions, leading to isolation and difficulties in social activities. Communication, the most common challenge reported by individuals with HL, involves the integration of various sensory inputs. Accurate assessment of communication ability involves not only evaluating how well speech is heard but also understanding how different sensory inputs are processed in the brain. Using the functional near-infrared spectroscopy (fNIRS) technique as an objective method, this pilot study explored speech performance and the activation patterns of the anterior prefrontal cortex (APFC) in individuals with normal hearing (NH) and HL. Twenty-six participants (14 with NH and 12 with HL) completed speech and fNIRS testing in auditory only (AO), visual only (VO), and audiovisual (AV) conditions with five trials per condition. The participants completed a listen-and-repeat task and speech performance was evaluated using percent-correct scores. Hemodynamic responses in APFC were analyzed to investigate the activation patterns in each test condition. Both groups showed the best speech performance in AV, followed by AO and VO. While the NH group showed better speech performance than the HL group in AV and AO, the HL group showed better performance in VO. In terms of APFC activation patterns, both groups exhibited activation in the right anterior medial PFC across AO, VO, and AV, but in VO, the HL group showed activation in that left anterior lateral PFC. These pilot study results are consistent with previous findings showing that individuals with HL exhibit lower speech performance and the provision of visual information is beneficial for speech understanding regardless of HL. However, different patterns of APFC activation observed through fNIRS indicate that the areas engaged in processing various sensory inputs during communication may differ depending on the presence of HL.

Background: Identifying the temporal and spectral information in sound is important for understanding speech; indeed, a person who has good spectral resolution usually shows good speech recognition performance. The spectral ripple discrimination (SRD) test is often used to behaviorally determine spectral resolution capacity. However, although the SRD test is useful, it is difficult to apply to populations who cannot execute the behavioral task, such as younger children and people with disabilities. In this study, an objective approach using spectral ripple (SR) stimuli to evoke the acoustic change complex (ACC) response was investigated to determine whether it could objectively evaluate the spectral resolution ability of subjects with normal hearing (NH) and those with hearing loss (HL). Method: Ten subjects with NH and eight with HL were enrolled in this study. All subjects completed the behavioral SRD test and the objective SR-ACC test. Additionally, the HL subjects completed speech perception performance tests while wearing hearing aids. Results: In the SRD test, the average thresholds were 6.48 and 1.52 ripples per octave (RPO) for the NH and HL groups, respectively, while in the SR-ACC test, they were 4.90 and 1.35 RPO, respectively. There was a significant difference in the average thresholds between the two groups for the SRD (p < 0.001) and the SR-ACC (p < 0.001) tests. A significant positive correlation was observed between the SRD and SR-ACC tests (ρ = 0.829, p < 0.001). In the HL group, there was a statistically significant relationship between speech recognition performance in noisy conditions and the SR-ACC threshold (ρ = 0.911, p < 0.001 in Sentence score of Korean Speech Audiometry (KSA)). Conclusions: The results supported the feasibility of the SR-ACC test to objectively evaluate auditory spectral resolution in individuals with HL. This test has potential for use in individuals with HL who are unable to complete the behavioral task associated with the SRD test; therefore, it is proposed as a more inclusive alternative to the SRD test.

Speech acceptability is an indicator that shows the degree to which a listener feels natural after listening to the speaker. When it comes to individuals with hearing impairment, speech acceptability is an important factor for aural rehabilitation as it is related to their social adaptation. Speech acceptability evaluates the naturalness of speech, so it may not necessarily align with the accuracy of articulation or the level of speech intelligibility. Therefore, it is essential to evaluate speech acceptability along with speech comprehension during aural rehabilitation process. However, most aural rehabilitation sessions primarily focus on segmental aspects and currently, there is no consensus on a definition or evaluation method for speech acceptability. The purpose of this study is to discuss the importance of speech acceptability, which is still rarely included in the speech evaluation process for those with hearing impairment.

Background: It has been reported in many previous studies that the lack of auditory input due to hearing loss (HL) can induce changes in the brain. However, most of these studies have focused on individuals with pre-lingual HL and have predominantly compared the characteristics of those with normal hearing (NH) to cochlear implant (CI) users in children. This study examined the visual and auditory evoked potential characteristics in NH listeners, individuals with bilateral HL, and CI users, including those with single-sided deafness. Methods: A total of sixteen participants (seven NH listeners, four individuals with bilateral sensorineural HL, and five CI users) completed speech testing in quiet and noise and evoked potential testing. For speech testing, the Korean version of the Hearing in Noise Test was used to assess individuals’ speech understanding ability in quiet and in noise (noise from the front, +90 degrees, and −90 degrees). For evoked potential testing, visual and auditory (1000 Hz, /ba/, and /da/) evoked potentials were measured. Results: The results showed that CI users understood speech better than those with HL in all conditions except for the noise from +90 and −90 degrees. In the CI group, a decrease in P1 amplitudes was noted across all channels after implantation. The NH group exhibited the highest amplitudes, followed by the HL group, with the CI group (post-CI) showing the lowest amplitudes. In terms of auditory evoked potentials, the smallest amplitude was observed in the pre-CI condition regardless of the type of stimulus. Conclusions: To the best of our knowledge, this is the first study that examined visual and auditory evoked potentials based on various hearing profiles. The characteristics of evoked potentials varied across participant groups, and further studies with CI users are necessary, as there are significant challenges in collecting and analyzing evoked potentials due to artifact issues on the CI side.

Background and Objectives: Cochlear implants (CIs) are well known to improve audibility and speech recognition in individuals with hearing loss, but some individuals still struggle with many aspects in communication, such as prosody. This study explores how prosodic elements are perceived by those with normal hearing (NH) and CIs.Subjects and Methods: Thirteen individuals with NH and thirteen CI users participated in this study and completed speech perception, speech prosody perception, speech prosody production, pitch difference discrimination, and melodic contour perception testing.Results: NH listeners performed significantly better than CI users on speech perception, speech prosody perception (except for words with neutral meaning and a negative prosody change and when words were repeated twice), pitch difference discrimination, and melodic contour perception testing. No statistical significance was observed for speech prosody production for both groups.Conclusions: Compared to NH listeners, CI users had limited ability to recognize prosodic elements. The study findings highlight the necessity of an assessment tool and signal processing algorithm for CIs, specifically targeting prosodic elements in clinical settings.

Background: There has been a growing interest in the provision of smartphone- or internet-based tinnitus management. Studies have shown a positive impact of the smartphone applications on tinnitus symptoms. However, research into a relatively long-term effect of these applications on tinnitus relief as well as sound preferences has been sparse. This study explored the potential benefit of a tinnitus application in tinnitus relief over a period of six months. Methods: Twenty-two participants with subjective tinnitus were enrolled in the study. Puretone audiometry, tinnitus pitch and loudness matching, stress assessment, and questionnaires were completed at the initial visit and three and six months after the first visit. The participants used the tinnitus application for six months. Results: A significant reduction in subjective tinnitus loudness and annoyance and subjective stress level was observed. The Tinnitus Handicap Inventory scores were also significantly decreased after six months. The participants also reported high satisfaction with the application. Music and environmental sounds were the most preferred sound stimuli. Conclusions: The findings of this study demonstrate the potential benefit of the tinnitus application for tinnitus improvement.

This study explores speech recognition characteristics in background noise and music between normal hearing (NH) listeners, hearing aid (HA) users and cochlear implant (CI) users.Sixty individuals participated in the study: 20 with NH, 20 HA users, and 20 CI users. HA and CI users had a Categories of Auditory Performance score of 6 and open set sentence recognition of 85% or higher. They had been using the devices for at least one year. Babble noise (BN), piano solo (PS), piano + violin (PV), and piano + chorus (PC) were presented at +5- and +10 dB signal-to-noise ratio (SNR). The participants were asked to listen and repeat words and sentences from the Korean Standard Sentence List for Adults. At +5- and +10 dB SNRs, CI users performed worse than those with NH on word and sentence recognition in BN, PS, PV, and PC. HA users outperformed CI users in all conditions. Those with NH showed better sentence recognition than HA users across all conditions at +5 dB SNR and better word recognition in PV and BN at +5 dB SNR and in PC at +10 dB SNR. Correlational analysis revealed that the percentage of life with hearing loss before CI was not correlated with sentence and word recognition across all conditions in both SNRs. Statistically significant negative correlations were observed between the duration of deafness and sentence and word recognition in some conditions. Despite individuals with HL performing well on clinical tests, background music can still interfere with communication for those using hearing devices. To accurately evaluate individuals’ communication abilities clinical tools that include background music need to be developed. Studies using different types of music could help develop and standardize such tools for assessing speech and language abilities in individuals with hearing loss.

Face masks are mandatory during the COVID-19 pandemic, leading to attenuation of sound energy and loss of visual cues which are important for communication. This study explores how a face mask affects speech performance for individuals with and without hearing loss. Four video recordings (a female speaker with and without a face mask and a male speaker with and without a face mask) were used to examine individuals’ speech performance. The participants completed a listen-and-repeat task while watching four types of video recordings. Acoustic characteristics of speech signals based on mask type (no mask, surgical, and N95) were also examined. The availability of visual cues was beneficial for speech understanding—both groups showed significant improvements in speech perception when they were able to see the speaker without the mask. However, when the speakers were wearing the mask, no statistical significance was observed between no visual cues and visual cues conditions. Findings of the study demonstrate that provision of visual cues is beneficial for speech perception for individuals with normal hearing and hearing impairment. This study adds value to the importance of the use of communication strategies during the pandemic where visual information is lost due to the face mask.

Purpose: This study explores the influence of the noise-canceling technology in commercial earphones on sound pressure levels and preferred listening levels in terms of hearing protection. Materials and Methods: Thirty individuals completed puretone audiometry and real-ear measurements to assess sound pressure levels at the level of the eardrum with and without the activation of the noise-canceling function. The Knowles Electronics Manikin for Acoustic Research was used to investigate the acoustic characteristics of two environmental sounds (bus and café). Two types of earphones (wireless and wired canal type) were utilized in the study. Results: For both bus and café noises, in the low-frequency range, sound pressure levels were significantly decreased for all types of earphones when the noise-canceling function was turned on. The same results were observed for the whole frequency range. In terms of preferred listening levels, the wireless canal type and wired canal type earphones showed significant reduction in volume levels. Conclusion: The findings of the study show that for both low- and whole frequency range, the use of noise-canceling function significantly decreases the sound pressure levels of the signal for all styles of earphones, suggesting a potential of the noise-canceling technology in hearing protection.