Comparison of Traditional Impression and 3D Ear Scanning Techniques, Earmold Comfort, and Audiology Clinical Implications: A Pilot Study.

This study investigated clinical aspects of the traditional ear impression and 3D ear scanning techniques. Adult earmold-users and non-users participated in this study. The earmold-users also participated in the earmold comfort comparison study by wearing earmolds from both techniques, one set a week according to a randomized sequence. Multiple clinical aspects of both techniques according to the participants and audiology professionals were recorded. Results revealed a preference for the 3D-scanning technique, which was perceived as more comfortable although both techniques were perceived as safe. Although the earmolds might have issues from both techniques, there was no significant difference in the perception of earmolds. Experience with the specific technique can affect the responses from the professionals. Compared to the traditional technique, 3D-scans had higher fixed but less variable costs and procedure times. A special clinical case was included and indicated that 3D-scans could be an option for specific patients. This study led to a better understanding of the two techniques clinically. With increasing involvement of new technology and more young professionals joining the profession of audiology, 3D ear scanning could be a viable consideration for audiology practices.

Sound Localization of Listeners With Normal Hearing, Impaired Hearing, Hearing Aids, Bone-Anchored Hearing Instruments, and Cochlear Implants: A Review.

PURPOSE: This review article reviews the contemporary studies of localization ability for different populations in different listening environments and provides possible future research directions. CONCLUSIONS: The ability to accurately localize a sound source relying on three cues (interaural time difference, interaural level difference, and spectral cues) is important for communication, learning, and safety. Confounding effects including noise and reverberation, which exist in common listening environments, mask or alter localization cues and negatively affect localization performance. Hearing loss, a common public health issue, also affects localization accuracy. Although hearing devices have been developed to provide excellent audibility of speech signals, less attention has been paid to preserving and replicating crucial localization cues. Unique challenges are faced by users of various hearing devices, including hearing aids, bone-anchored hearing instruments, and cochlear implants. Hearing aids have failed to consistently improve localization performance and, in some cases, significantly impair sound localization. Bone-conduction hearing instruments show little to no benefit for sound localization performance in most cases, although some improvement is seen in binaural users. Although cochlear implants provide great hearing benefit to individuals with severe-to-profound sensorineural hearing loss, cochlear implant users have significant difficulty localizing sound, even with two implants. However, technologies in each of these areas are advancing to reduce interference with desired sound signals and preserve localization cues to help users achieve better hearing and sound localization in real-life environments.

Dual functions of epigallocatechin gallate surface-modified Au nanorods@selenium composites for near-infrared-II light-responsive synergistic antibacterial therapy.

Diseases caused by bacterial infections pose ever-increasing threats to human health, making it important to explore alternative antibacterial strategies. Herein, epigallocatechin gallate (EGCG) surface-modified Au nanorods@selenium composites (ASE NPs) were developed for synergistic NIR-II light-responsive antibacterial therapy. In vitro antibacterial experiments demonstrated the improved antibacterial effect of ASE NPs against Staphylococcus aureus (S. aureus) compared with EGCG alone. In addition, in vivo studies demonstrated that ASE NPs cured skin wound infections and sepsis in mice caused by S. aureus. Au nanorods with excellent photothermal conversion realized synergistic photothermal therapy (PTT) in the NIR-II biowindow with an improved penetration depth at a low power density. More importantly, toxicity analysis showed that the composites had no toxic effects on major organs. Thus, the EGCG surface-modified Au nanorods@selenium composites with an NIR-II light-responsive synergistic activity hold great promise for the effective treatment of drug-resistant bacterial infections.

Potential of Bacillus velezensis as a probiotic in animal feed: a review.

Bacillus velezensis is a plant growth-promoting bacterium that can also inhibit plant pathogens. However, based on its properties, it is emerging as a probiotic in animal feed. This review focuses on the potential characteristics of B. velezensis for use as a probiotic in the animal feed industry. The review was conducted by collecting recently published articles from peer-reviewed journals. Google Scholar and PubMed were used as search engines to access published literature. Based on the information obtained, the data were divided into three groups to discuss the (i) probiotic characteristics of B. velezensis, (ii) probiotic potential for fish, and (iii) the future potential of this species to be developed as a probiotic for the animal feed industry. Different strains of B. velezensis isolated from different sources were found to have the ability to produce antimicrobial compounds and have a beneficial effect on the gut microbiota, with the potential to be a candidate probiotic in the animal feed industry. This review provides valuable information about the characteristics of B. velezensis, which can provide researchers with a better understanding of the use of this species in the animal feed industry.

Conventional audiometry, extended high-frequency audiometry, and DPOAEs in youth recreational firearm users.

To determine if conventional audiometry, EHFA, and pDPOAEs are useful as early indicators of cochlear damage from recreational firearm impulse noise exposure in youth firearm users. Quantitative cross-sectional descriptive pilot study. Descriptive statistics and MANOVA with post hoc Tukey Honestly Significant Difference test were used to compare pDPOAEs (1-10 kHz), conventional audiometry (0.25-8 kHz), and EHFA (10-16 kHz) in YFUs. 25 YFUs (n = 11 7-12 years; n = 14 13-17 years) with self-reported poor compliance with hearing protector device wear. Conventional audiometric thresholds at 2-, 3- and 4 kHz were significantly poorer than normal but did not distinguish between older and younger YFUs or between the GBE and the contralateral ear. EHFA thresholds at 14- and 16 kHz were significantly poorer than for other frequencies, and differentiate between older and younger youths, but do not distinguish the GBE from the contralateral ear. Finally, pDPOAE levels were significantly reduced at 8- and 10 kHz but did not show any differences for the younger versus older YFUs or for the GBE from the contralateral ear. Conclusion: Both EHFA and pDPOAEs provide early evidence of NIHL in YFUs, and may be useful for the early detection of NIHL in YFUs.

Combined Effects of Noise and Reverberation on Sound Localization for Listeners With Normal Hearing and Bilateral Cochlear Implants.

PURPOSE: This study examined the individual and combined effects of noise and reverberation on the ability of listeners with normal hearing (NH) and with bilateral cochlear implants (BCIs) to localize speech. METHOD: Six adults with BCIs and 10 with NH participated. All subjects completed a virtual localization test in quiet and at 0-, -4-, and -8-dB signal-to-noise ratios (SNRs) in simulated anechoic and reverberant (0.2-, 0.6-, and 0.9-s RT60) environments. BCI users were also tested at +8- and +4-dB SNR. A 3-word phrase was presented at 70 dB SPL from 9 simulated locations in the frontal horizontal plane (±90°), with the noise source at 0°. RESULTS: BCIs users had significantly poorer localization than listeners with NH in all conditions. BCI users' performance started to decrease at a higher SNR (+4 dB) and shorter RT60 (0.2 s) than listeners with NH (-4 dB and 0.6 s). The combination of noise and reverberation began to degrade localization of BCI users at a higher SNR and a shorter RT60 than listeners with NH. CONCLUSION: The clear effect of noise and reverberation on the performance of BCI users provides information that should be useful for refining cochlear implant processing strategies and developing cochlear implant rehabilitation plans to optimize binaural benefit for BCI users in everyday listening situations.

Effects of noise and reverberation on virtual sound localization for listeners with bilateral cochlear implants.

OBJECTIVE: This study investigated the effects of both noise and reverberation on the ability of listeners with bilateral cochlear implants (BCIs) to localize and the feasibility of using a virtual localization test to evaluate BCI users. DESIGN: Seven adults with normal hearing (NH) and two adults with BCIs participated. All subjects completed the virtual localization test in quiet and at 0, -4, -8 dB signal-to-noise ratio in simulated anechoic and reverberant environments. BCI users were also tested at +4 dB signal-to-noise ratio. The noise source was at 0°. A three-word phrase was presented at 70 dB SPL from nine simulated locations in the frontal horizontal plane (±90°). RESULTS: Results revealed significantly poorer localization accuracy for BCI users than NH listeners in all conditions. Significant reverberation effects were observed for BCI users but not listeners with NH. CONCLUSION: Noise and reverberation have a significant effect on BCI users, and their localization ability can be evaluated using these virtual tests.

Spectral and temporal cues for phoneme recognition in noise.

Cochlear implant users receive limited spectral and temporal information. Their speech recognition deteriorates dramatically in noise. The aim of the present study was to determine the relative contributions of spectral and temporal cues to speech recognition in noise. Spectral information was manipulated by varying the number of channels from 2 to 32 in a noise-excited vocoder. Temporal information was manipulated by varying the low-pass cutoff frequency of the envelope extractor from 1 to 512 Hz. Ten normal-hearing, native speakers of English participated in tests of phoneme recognition using vocoder processed consonants and vowels under three conditions (quiet, and +6 and 0 dB signal-to-noise ratios). The number of channels required for vowel-recognition performance to plateau increased from 12 in quiet to 16-24 in the two noise conditions. However, for consonant recognition, no further improvement in performance was evident when the number of channels was > or =12 in any of the three conditions. The contribution of temporal cues for phoneme recognition showed a similar pattern in both quiet and noise conditions. Similar to the quiet conditions, there was a trade-off between temporal and spectral cues for phoneme recognition in noise.