RESUMO
Ambient noise constrains the evolution of acoustic signals and hearing. An earlier fitness model showed that the trade-off between sound detection and recognition helps predict the best level of auditory sensitivity for acoustic communication in noise. Here, the early model is improved to investigate the effects of different noise masking conditions and signal-to-noise ratios (SNRs). It is revealed that low sensitivity is expected for acoustic communication over short distances in complex noisy environments provided missed sound recognition is costly. By contrast, high sensitivity is expected for acoustic communication over long distances in quieter habitats or when sounds are received with good SNRs under unfavorable noise conditions. High sensitivity is also expected in noisy environments characterized by one dominant source of noise with a fairly constant spectrum (running-water noise) or when sounds are processed using anti-masking strategies favoring the detection and recognition of sound embedded in noise. These predictions help explain unexpected findings that do not fit with the current view on the effects of environmental selection on signal and sensitivity. Model predictions are compared with those of models of signal detection in noisy conditions and results of empirical studies.
Assuntos
Audição , Ruído , Ruído/efeitos adversos , Ecossistema , Acústica , Testes Auditivos , Mascaramento Perceptivo , Estimulação AcústicaRESUMO
Although averaging is effective in reducing noise, its efficiency rapidly decreases beyond several hundred averages. Depending on environmental and patient noise levels, several hundred averages may be insufficient for informed clinical decision making. The predictable nature of the otoacoustic emission (OAE) and noise during time-synchronous averaging implicates the use of predictive modeling as an alternative to increased averaging when noise is high. Click-evoked OAEs were measured in 98, normal-hearing subjects. Average OAE and noise levels were calculated for subsets of the total number of averages and then fit using variants of a power function. The accuracy of the models was quantified as the difference between the measured value and model output. Models were used to predict the OAE signal-to-noise ratio (SNR) for a criterion noise level. Based on predictions, the OAE was categorized as present or absent. Model-based decisions were compared to decisions from direct measurements. Model accuracy improved as the number of averages (and SNR in the case of OAEs) from which the model was derived increased. Model-based classifications permitted correct categorization of the OAE status from fewer averages than measurement-based classifications. Furthermore, model-based predictions resulted in fewer false positives (i.e., absent OAE despite normal hearing).
Assuntos
Ruído , Emissões Otoacústicas Espontâneas , Humanos , Razão Sinal-Ruído , Emissões Otoacústicas Espontâneas/fisiologia , Ruído/efeitos adversos , Testes Auditivos/métodos , Estimulação AcústicaRESUMO
Front-back reversals (FBRs) in sound-source localization tasks due to cone-of-confusion errors on the azimuth plane occur with some regularity, and their occurrence is listener-dependent. There are fewer FBRs for wideband, high-frequency sounds than for low-frequency sounds presumably because the sources of low-frequency sounds are localized on the basis of interaural differences (interaural time and level differences), which can lead to ambiguous responses. Spectral cues can aid in determining sound-source locations for wideband, high-frequency sounds, and such spectral cues do not lead to ambiguous responses. However, to what extent spectral features might aid sound-source localization is still not known. This paper explores conditions in which the spectral profile of two-octave wide noise bands, whose sources were localized on the azimuth plane, were randomly varied. The experiment demonstrated that such spectral profile randomization increased FBRs for high-frequency noise bands, presumably because whatever spectral features are used for sound-source localization were no longer as useful for resolving FBRs, and listeners relied on interaural differences for sound-source localization, which led to response ambiguities. Additionally, head rotation decreased FBRs in all cases, even when FBRs increased due to spectral profile randomization. In all cases, the occurrence of FBRs was listener-dependent.
Assuntos
Sinais (Psicologia) , Localização de Som , Estimulação Acústica , Ruído/efeitos adversos , Som , Localização de Som/fisiologia , HumanosRESUMO
The auditory steady-state response (ASSR) was continuously measured in two bottlenose dolphins during impulse noise exposures to determine whether observed head movements coincided with actual changes to auditory system sensitivity. Impulses were generated by a seismic air gun at a fixed inter-pulse interval of 10 s. ASSR amplitudes were extracted from the instantaneous electroencephalogram using coherent averaging within a sliding analysis window. A decline in ASSR amplitude was seen during the time interval between air gun impulses, followed by an elevation in ASSR amplitude immediately after each impulse. Similar patterns were not observed during control trials where air gun impulses were not generated. The results suggest that the dolphins learned the timing of the impulse noise sequences and lowered their hearing sensitivity before each impulse, presumably to lessen the auditory effects of the noise. The specific mechanisms responsible for the observed effects are at present unknown.
Assuntos
Golfinho Nariz-de-Garrafa , Audição , Animais , Limiar Auditivo/fisiologia , Testes Auditivos/métodos , Ruído/efeitos adversos , Golfinho Nariz-de-Garrafa/fisiologia , Estimulação Acústica/métodosRESUMO
The lateralization of processing in the auditory cortex for different acoustic parameters differs depending on stimuli and tasks. Thus, processing complex auditory stimuli requires an efficient hemispheric interaction. Anatomical connectivity decreases with aging and consequently affects the functional interaction between the left and right auditory cortex and lateralization of auditory processing. Here we studied with magnetic resonance imaging the effect of aging on the lateralization of processing and hemispheric interaction during two tasks utilizing the contralateral noise procedure. Categorization of tones according to their direction of frequency modulations (FM) is known to be processed mainly in the right auditory cortex. Sequential comparison of the same tones according to their FM direction strongly involves additionally the left auditory cortex and therefore a stronger hemispheric interaction than the categorization task. The results showed that older adults more strongly recruit the auditory cortex especially during the comparison task that requires stronger hemispheric interaction. This was the case although the task difficulty was adapted to achieve similar performance as the younger adults. Additionally, functional connectivity from auditory cortex to other brain areas was stronger in older than younger adults especially during the comparison task. Diffusion tensor imaging data showed a reduction in fractional anisotropy and an increase in mean diffusivity in the corpus callosum of older adults compared to younger adults. These changes indicate a reduction of anatomical interhemispheric connections in older adults that makes larger processing capacity necessary when tasks require functional hemispheric interaction.
Assuntos
Imagem de Tensor de Difusão , Lateralidade Funcional , Estimulação Acústica/métodos , Percepção Auditiva , Ruído/efeitos adversos , Imageamento por Ressonância Magnética/métodosRESUMO
Hearing is one of the most important human perception forms, and humans can capture the movement of sound in complex environments. On the basis of this phenomenon, this study explored the possibility of eliciting a steady-state brain response in an intermittent periodic motion sound source. In this study, a novel discrete continuous and orderly change of sound source positions stimulation paradigm was designed based on virtual sound using head-related transfer functions (HRTFs). And then the auditory motion stimulation paradigms with different noise levels were designed by changing the signal-to-noise ratio (SNR). The characteristics of brain response and the effects of different noises on brain response were studied by analyzing electroencephalogram (EEG) signals evoked by the proposed stimulation. Experimental results showed that the proposed paradigm could elicit a novel steady-state auditory evoked potential (AEP), i.e., steady-state motion auditory evoked potential (SSMAEP). And moderate noise could enhance SSMAEP amplitude and corresponding brain connectivity. This study enriches the types of AEPs and provides insights into the mechanism of brain processing of motion sound sources and the impact of noise on brain processing.
Assuntos
Audição , Ruído , Humanos , Estimulação Acústica/métodos , Ruído/efeitos adversos , Audição/fisiologia , Potenciais Evocados Auditivos/fisiologia , EletroencefalografiaRESUMO
OBJECTIVE: The medial olivocochlear (MOC) reflex provides unmasking of sounds in noise, but its contribution to speech-in-noise perception remains unclear due to conflicting results. This study determined associations between MOC reflex strength and sentence recognition in noise in individuals with normal hearing. DESIGN: MOC reflex strength was assessed using contralateral inhibition of transient-evoked otoacoustic emissions (TEOAEs). Scores on the AzBio sentence task were quantified at three signal-to-noise ratios (SNRs). Additionally, slope and threshold of the psychometric function were computed. Associations between MOC reflex strength and speech-in-noise outcomes were assessed using Spearman rank correlations. STUDY SAMPLE: Nineteen young adults with normal hearing participated, with data from 17 individuals (mean age = 21.8 years) included in the analysis. RESULTS: Contralateral noise significantly decreased the amplitude of TEOAEs. A range of contralateral inhibition values was exhibited across participants. Scores increased significantly with increasing SNR. Contrary to hypotheses, there were no significant correlations between MOC reflex strength and score, nor were there any significant correlations between MOC reflex strength and measures of the psychometric function. CONCLUSIONS: Results found no significant monotonic relationship between MOC reflex strength and sentence recognition in noise. Future work is needed to determine the functional role of the MOC reflex.
Assuntos
Núcleo Olivar , Emissões Otoacústicas Espontâneas , Adulto Jovem , Humanos , Adulto , Emissões Otoacústicas Espontâneas/fisiologia , Cóclea/fisiologia , Ruído/efeitos adversos , Reflexo/fisiologia , Estimulação AcústicaRESUMO
Noise annoyance has been often reported as one of the main adverse effects of noise exposure on human health, and there is consensus that it relates to several factors going beyond the mere energy content of the signal. Research has historically focused on a limited set of sound sources (e.g., transport and industrial noise); only more recently is attention being given to more holistic aspects of urban acoustic environments and the role they play in the noise annoyance perceptual construct. This is the main approach promoted in soundscape studies, looking at both wanted and unwanted sounds. In this study, three specific aspects were investigated, namely: (1) the effect of different sound sources combinations, (2) the number of sound sources present in the soundscape, and (3) the presence of individual sound source, on noise annoyance perception. For this purpose, a large-scale online experiment was carried out with 1.2k+ participants, using 2.8k+ audio recordings of complex urban acoustic environments to investigate how they would influence the perceived noise annoyance. Results showed that: (1) the combinations of different sound sources were not important, compared, instead, to the number of sound sources identified in the soundscape recording (regardless of sound sources type); (2) the annoyance ratings expressed a minimum when any two clearly distinguishable sound sources were present in a given urban soundscape; and (3) the presence (either in isolation or combination) of traffic-related sound sources increases noise annoyance, while the presence (either in isolation or combination) of nature-related sound sources decreases noise annoyance.
Assuntos
Percepção Auditiva , Ruído , Humanos , Ruído/efeitos adversos , Som , Acústica , IndústriasRESUMO
The installation of marine renewable energy devices (MREDs, wind turbines and converters of wave, tidal and ocean thermal energy) has increased quickly in the last decade. There is a lack of knowledge concerning the effects of MREDs on benthic invertebrates that live in contact with the seabed. The European common cuttlefish (Sepia officinalis) is the most abundant cephalopod in the Northeast Atlantic and one of the three most valuable resources for English Channel fisheries. A project to build an offshore wind farm in the French bay of Saint-Brieuc, near the English Channel, raised concern about the possible acoustic impact on local cuttlefish communities. In this study, consisting of six exposure experiments, three types of noise were considered: 3 levels of pile-driving and 3 levels of drilling. The objectives were to assess possible associated changes in hatching and larva survival, and behavioural and ultrastructural effects on sensory organs of all life stages of S. officinalis populations. After exposure, damage was observed in the statocyst sensory epithelia (hair cell extrusion) in adults compared to controls, and no anti-predator reaction was observed. The exposed larvae showed a decreased survival rate with an increasing received sound level when they were exposed to maximum pile-driving and drilling sound levels (170 dB re 1 µPa2 and 167 dB re 1 µPa2, respectively). However, sound pressure levels's lower than 163 dB re 1 µPa2 were not found to elicit severe damage. Simulating a scenario of immobile organisms, eggs were exposed to a combination of both pile driving and drilling as they would be exposed to all operations without a chance to escape. In this scenario a decrease of hatching success was observed with increasing received sound levels.
Assuntos
Perda Auditiva Provocada por Ruído , Estimulação Acústica , Animais , Decapodiformes , Larva , Ruído/efeitos adversos , SomRESUMO
Intense sound sources, such as pile driving, airguns, and military sonars, have the potential to inflict hearing loss in marine mammals and are, therefore, regulated in many countries. The most recent criteria for noise induced hearing loss are based on empirical data collected until 2015 and recommend frequency-weighted and species group-specific thresholds to predict the onset of temporary threshold shift (TTS). Here, evidence made available after 2015 in light of the current criteria for two functional hearing groups is reviewed. For impulsive sounds (from pile driving and air guns), there is strong support for the current threshold for very high frequency cetaceans, including harbor porpoises (Phocoena phocoena). Less strong support also exists for the threshold for phocid seals in water, including harbor seals (Phoca vitulina). For non-impulsive sounds, there is good correspondence between exposure functions and empirical thresholds below 10 kHz for porpoises (applicable to assessment and regulation of military sonars) and between 3 and 16 kHz for seals. Above 10 kHz for porpoises and outside of the range 3-16 kHz for seals, there are substantial differences (up to 35 dB) between the predicted thresholds for TTS and empirical results. These discrepancies call for further studies.
Assuntos
Perda Auditiva Provocada por Ruído , Phoca , Phocoena , Estimulação Acústica , Animais , Fadiga Auditiva , Perda Auditiva Provocada por Ruído/diagnóstico , Perda Auditiva Provocada por Ruído/etiologia , Perda Auditiva Provocada por Ruído/veterinária , Ruído/efeitos adversos , Phocoena/fisiologia , Psicoacústica , Espectrografia do SomRESUMO
BACKGROUND: Tinnitus is the result of aberrant neuronal activity. As a novel treatment form, neuromodulation is used to modify neuronal activity of brain areas involved in tinnitus generation. Among the different forms of electric stimulation, transcranial random noise stimulation (tRNS) has been shown to be a promising treatment option for tinnitus. In addition, recent studies indicate that the reduction in tinnitus can be more pronounced when different modalities of stimulation techniques are combined ("bimodal stimulation"). TRNS can be used in combination with acoustic stimulation (AS), a further treatment option recognized in the literature. The aim of the proposed study is to investigate whether simultaneous tRNS and AS improve levels of tinnitus loudness and distress. METHODS: The intervention consists of bilateral high-definition tRNS (HD-tRNS) over the auditory cortex combined with the application of AS which is studied in a crossover design. The visits will be performed in 26 sessions. There will be 20 treatment sessions, divided into two blocks: active and sham HD-tRNS. Within the blocks, the interventions are divided into group A: HD-tRNS and AS, and group B: HD-tRNS alone. Furthermore, in addition to the assessments directly following the intervention sessions, there will be six extra sessions performed subsequently at the end of each block, after a period of some days (follow-ups 1 and 2) and a month after the last intervention (C). Primary outcome measures are analog scales for evaluation of subjective tinnitus loudness and distress, and the audiological measurement of minimum masking level (MML). Secondary outcome measures are brain activity as measured by electroencephalography and standardized questionnaires for evaluating tinnitus distress and severity. DISCUSSION: To the best of our knowledge, this is the first study which uses HD-tRNS combined with AS for tinnitus treatment. The crossover design permits the comparison between HD-tRNS active vs. sham and with vs. without AS. Thus, it will be possible to evaluate the efficacy of the combined approach to HD-tRNS alone. In addition, the use of different objective and subjective evaluations for tinnitus enable more reliable and valid results. TRIAL REGISTRATION: Swiss Ethics Committee (BASEC-Nr. 2020-02027); Swiss Federal Complementary Database (kofam.ch: SNCTP000004051 ); and ClinicalTrials.gov (clinicaltrials.gov: NCT04551404 ).
Assuntos
Estimulação Acústica , Zumbido , Estimulação Transcraniana por Corrente Contínua , Método Duplo-Cego , Humanos , Ruído/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Zumbido/terapiaRESUMO
The aviation sector is rapidly evolving with more electric propulsion systems and a variety of new technologies of vertical take-off and landing manned and unmanned aerial vehicles. Community noise impact is one of the main barriers for the wider adoption of these new vehicles. Within the framework of a perception-driven engineering approach, this paper investigates the relationship between sound quality and first order physical parameters in rotor systems to aid design. Three case studies are considered: (i) contra-rotating versus single rotor systems, (ii) varying blade diameter and thrust in both contra-rotating and single rotor systems, and (iii) varying rotor-rotor axial spacing in contra-rotating systems. The outcomes of a listening experiment, where participants assessed a series of sound stimuli with varying design parameters, allow a better understanding of the annoyance induced by rotor noise. Further to this, a psychoacoustic annoyance model optimised for rotor noise has been formulated. The model includes a novel psychoacoustic function to account for the perceptual effect of impulsiveness. The significance of the proposed model lies in the quantification of the effects of psychoacoustic factors, such as loudness as the dominant factor, and also tonality, high frequency content, temporal fluctuations, and impulsiveness on rotor noise annoyance.
Assuntos
Ruído , Som , Estimulação Acústica , Percepção Auditiva , Humanos , Ruído/efeitos adversos , PsicoacústicaRESUMO
Sleep is an essential need for patients admitted to coronary care units. The present clinical trial aimed to determine the effect of using eye masks and earplugs on the sleep quality of patients with coronary heart disease (CHD). A total of 68 eligible patients with CHD were randomly allocated into four groups of 17 (control, eye masks, earplugs, and eye masks with earplugs). All three interventions were performed during the night from 10:00 p.m. to 7:00 a.m. the next day. The outcomes were the quality of sleep, measured by the Verran and Snyder-Halpern (VSH) Sleep Scale, and the urinary levels of nocturnal melatonin and cortisol, measured by urine samples taken during the night (from 10:00 p.m. to 7:00 a.m.). The study outcomes were measured on the third and fourth days. Sleep disturbance was statistically significantly lower in patients with earplugs (visual analogue scale mean difference [MD]: 74.31 mm, SE: 11.34, p = 0.001). Sleep effectiveness was statistically significantly higher in patients with eye mask (MD: 36.88 mm, SE: 8.75, p = 0.001). The need for sleep supplementation was statistically significantly lower in patients with eye masks (MD: 39.79 mm, SE: 7.23, p = 0.001). There was a significant difference in melatonin levels between eye masks and the control group (p = 0.03). For urinary cortisol levels, there were significant differences between eye masks and the control group (p = 0.007), earplugs and the control group (p = 0.001), and eye masks with earplugs and the control group (p = 0.006). The mean scores for comfort, effectiveness, and ease of use were highest for the group that used eye masks (2.88, 2.94, and 3.18, respectively). As a result, all three interventions improved the sleep quality of patients. However, the interventions had different effects on the three dimensions of the VSH Sleep Scale, as well as the urinary levels of cortisol and melatonin.
Assuntos
Dispositivos de Proteção das Orelhas , Melatonina , Unidades de Cuidados Coronarianos , Humanos , Hidrocortisona , Unidades de Terapia Intensiva , Ruído/efeitos adversos , Sono , Qualidade do SonoRESUMO
Stochastic sounds are useful to probe auditory memory, as they require listeners to learn unpredictable and novel patterns under controlled experimental conditions. Previous studies using white noise or random click trains have demonstrated rapid auditory learning. Here, we explored perceptual learning with a more parametrically variable stimulus. These "tone clouds" were defined as broadband combinations of tone pips at randomized frequencies and onset times. Varying the number of tones covered a perceptual range from individually audible pips to noise-like stimuli. Results showed that listeners could detect and learn repeating patterns in tone clouds. Task difficulty varied depending on the density of tone pips, with sparse tone clouds the easiest. Rapid learning of individual tone clouds was observed for all densities, with a roughly constant benefit of learning irrespective of baseline performance. Variations in task difficulty were correlated to amplitude modulations in an auditory model. Tone clouds thus provide a tool to probe auditory learning in a variety of task-difficulty settings, which could be useful for clinical or neurophysiological studies. They also show that rapid auditory learning operates over a wide range of spectrotemporal complexity, essentially from melodies to noise.
Assuntos
Aprendizagem , Ruído , Estimulação Acústica , Percepção Auditiva , Ruído/efeitos adversos , SomRESUMO
Marine traffic is the most pervasive underwater anthropogenic noise pollution which can mask acoustic communication in marine mammals and fish, but its effect in marine invertebrates remains unknown. Here, we performed an at sea experiment to study the potential of shipping noise to mask and alter lobster acoustic communication. We used hydrophones to record buzzing sounds and accelerometers to detect lobster carapace vibrations (i.e. the buzzing sounds' sources). We demonstrated that male individuals produced carapace vibrations under various ambient noise conditions, including heavy shipping noise. However, while the associated waterborne buzzing sounds could be recorded under natural ambient noise levels, they were masked by shipping noise. Additionally, lobsters significantly increased their call rates in presence of shipping noise, suggesting a vocal compensation due to the reduction of intraspecific communication. This study reports for the first time the potential acoustic masking of lobster acoustic communication by chronic anthropogenic noise pollution, which could affect ecologically important behaviors.
Assuntos
Nephropidae , Ruído , Acústica , Animais , Humanos , Masculino , Ruído/efeitos adversos , Navios , SomRESUMO
In this study we used functional near-infrared spectroscopy (fNIRS) to investigate neural responses in normal-hearing adults as a function of speech recognition accuracy, intelligibility of the speech stimulus, and the manner in which speech is distorted. Participants listened to sentences and reported aloud what they heard. Speech quality was distorted artificially by vocoding (simulated cochlear implant speech) or naturally by adding background noise. Each type of distortion included high and low-intelligibility conditions. Sentences in quiet were used as baseline comparison. fNIRS data were analyzed using a newly developed image reconstruction approach. First, elevated cortical responses in the middle temporal gyrus (MTG) and middle frontal gyrus (MFG) were associated with speech recognition during the low-intelligibility conditions. Second, activation in the MTG was associated with recognition of vocoded speech with low intelligibility, whereas MFG activity was largely driven by recognition of speech in background noise, suggesting that the cortical response varies as a function of distortion type. Lastly, an accuracy effect in the MFG demonstrated significantly higher activation during correct perception relative to incorrect perception of speech. These results suggest that normal-hearing adults (i.e., untrained listeners of vocoded stimuli) do not exploit the same attentional mechanisms of the frontal cortex used to resolve naturally degraded speech and may instead rely on segmental and phonetic analyses in the temporal lobe to discriminate vocoded speech.
Assuntos
Estimulação Acústica/métodos , Implantes Cocleares , Lobo Frontal/fisiologia , Inteligibilidade da Fala/fisiologia , Percepção da Fala/fisiologia , Lobo Temporal/fisiologia , Adolescente , Adulto , Feminino , Lobo Frontal/diagnóstico por imagem , Humanos , Masculino , Ruído/efeitos adversos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Lobo Temporal/diagnóstico por imagem , Adulto JovemRESUMO
OBJECTIVES/HYPOTHESIS: Tinnitus can develop due to, or be aggravated by, stress in a rat model. To investigate stress as a possible causal factor in the development of tinnitus, we designed an animal study that included tinnitus behavior and excitatory/inhibitory neurotransmitter expression after noise exposure as well as restraint stress. STUDY DESIGN: An experimental animal study. METHODS: Wistar rats were grouped according to single or double exposure to noise and restraint stress. The noise exposure (NE) group was subjected to 110 dB sound pressure level (SPL) of 16 kHz narrow-band noise (NBN) for 1 hour, and the restraint stress (RS) group was restrained for 1 hour with or without noise exposure. Gap prepulse inhibition of the acoustic startle (GPIAS) reflex was measured at an NBN of 16 kHz to investigate tinnitus development. Various immunohistopathologic and molecular biologic studies were undertaken to evaluate possible mechanisms of tinnitus development after noise and/or restraint stress. RESULTS: The RS-only group showed a reduced GPIAS response, which is a reliable sign of tinnitus development. In the double-stimulus groups, more tinnitus-development signs of reduced GPIAS responses were observed. The expression of γ-aminobutyric acid A receptor α1 (GABAAR α1) in the hippocampus decreased in the NEâRS group. Increased N-methyl-d-aspartate receptor1 intensities in the NEâRS group and decreased GABAAR α1 intensities in the RS and NEâRS groups were observed in the CA3 region of the hippocampus. CONCLUSIONS: Tinnitus appeared to develop after stress alone in this animal study. An imbalance in excitatory and inhibitory neurotransmitters in the hippocampus may be related to the development of tinnitus after acute NE and/or stress. LEVEL OF EVIDENCE: NA Laryngoscope, 131:2332-2340, 2021.
Assuntos
Região CA3 Hipocampal/patologia , Ruído/efeitos adversos , Estresse Psicológico/complicações , Zumbido/etiologia , Estimulação Acústica/efeitos adversos , Estimulação Acústica/métodos , Animais , Modelos Animais de Doenças , Humanos , Masculino , Ratos , Receptores de GABA-A/análise , Receptores de GABA-A/metabolismo , Receptores de N-Metil-D-Aspartato/análise , Receptores de N-Metil-D-Aspartato/metabolismo , Reflexo de Sobressalto , Estresse Psicológico/psicologia , Zumbido/diagnóstico , Zumbido/patologia , Zumbido/psicologiaRESUMO
OBJECTIVE: To evaluate the association of listening to music loudly through personal listening devices with cochlear synaptopathy in young adults. METHODS: Fifty healthy young adults selected among 109 volunteers were included in the study. Participants of high risk (n=25) and low risk (n=25) groups estimated according to ETDNL (estimated total daily noise level) were evaluated using pure tone audiometry, tympanometry, matrix test, electrocochleography (EcochG) and auditory brainstem response (ABR) to evaluate the occurrence of cochlear synaptopathy. RESULTS: Audiometric thresholds between the groups were not significantly different (p>0.05). High risk group participants showed poorer performance than the low-risk group on the TurMatrix test, in non-adaptive noise with -5 SNR and -7.5 SNR, and at the 50% understanding SNR level with headphones (p<0.01). There was no difference in the adaptive free field in noise test at which 50% understanding was achieved (p>0.05). The AP amplitudes on EcochG and wave V amplitudes on ABR were significantly smaller in the high-risk group (p<0.05). There was no association between ETDNL and I/V ratio on ABR. CONCLUSION: Poorer performance in TurMatrix and other electrophysiologic tests revealed the negative effect of personal listening devices on the auditory system. Our findings support the hypothesis that personal listening devices could cause cochlear synaptopathy. Long-term studies are needed to determine the effects of binaural hearing and duration of noise exposure on the auditory system.
Assuntos
Cóclea/patologia , Perda Auditiva Provocada por Ruído/etiologia , MP3-Player , Música , Smartphone , Estimulação Acústica , Adulto , Audiometria de Tons Puros , Limiar Auditivo , Cóclea/inervação , Cóclea/fisiopatologia , Potenciais Evocados Auditivos do Tronco Encefálico , Feminino , Voluntários Saudáveis , Perda Auditiva Provocada por Ruído/diagnóstico , Perda Auditiva Provocada por Ruído/fisiopatologia , Humanos , Masculino , Ruído/efeitos adversos , Adulto JovemRESUMO
Scalp-recorded frequency-following responses (FFRs) reflect a mixture of phase-locked activity across the auditory pathway. FFRs have been widely used as a neural barometer of complex listening skills, especially speech-in noise (SIN) perception. Applying individually optimized source reconstruction to speech-FFRs recorded via EEG (FFREEG), we assessed the relative contributions of subcortical [auditory nerve (AN), brainstem/midbrain (BS)] and cortical [bilateral primary auditory cortex, PAC] source generators with the aim of identifying which source(s) drive the brain-behavior relation between FFRs and SIN listening skills. We found FFR strength declined precipitously from AN to PAC, consistent with diminishing phase-locking along the ascending auditory neuroaxis. FFRs to the speech fundamental (F0) were robust to noise across sources, but were largest in subcortical sources (BS > AN > PAC). PAC FFRs were only weakly observed above the noise floor and only at the low pitch of speech (F0≈100 Hz). Brain-behavior regressions revealed (i) AN and BS FFRs were sufficient to describe listeners' QuickSIN scores and (ii) contrary to neuromagnetic (MEG) FFRs, neither left nor right PAC FFREEG related to SIN performance. Our findings suggest subcortical sources not only dominate the electrical FFR but also the link between speech-FFRs and SIN processing in normal-hearing adults as observed in previous EEG studies.
Assuntos
Estimulação Acústica/métodos , Córtex Auditivo/fisiologia , Vias Auditivas/fisiologia , Audição/fisiologia , Ruído/efeitos adversos , Percepção da Fala/fisiologia , Adulto , Eletroencefalografia/métodos , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Feminino , Humanos , Masculino , Adulto JovemRESUMO
The study is aimed to evaluate the protective impact of banana peel extract (BPE) following noise induce behavioral deficits in male mice. Animals were separated into two groups (control and test, 12 in each). Control mice were given drinking water, at the same time test group was given BPE (400 mg/kg; oral administration). Animals have received their respective treatment for 14 days. Mice were subdivided (n=6) into unstressed and stressed groups on day 15. Noise stress was given to the respective group for 4-h. Behavioral activities were monitored 24-h after the 4-h noise stress. Forced-swim-test, Elevated-plus-maze and light-dark-activity-box tests were performed for depression/anxiety-like behaviors respectively. Morris-water-maze assessment was used for memory. After behavioral tests animals were sacrificed and brain was detached for biochemical estimations and histopathological studies. In the present study, BPE produced anxiolytic and antidepressant-like effects and enhanced memory. Activity of antioxidant enzymes increased while levels of AChE and MDA decreased in BPE treated animals. Histopathological alterations induced by noise stress were also normalized by BPE. It is concluded that supplementation/administration of banana peel has preventive effects against anxiety, depression and memory impairment via its strong antioxidant potential following NS.