Noise Aversion Research Articles

A Review on the Influence of Noise on the Welfare of Dogs

The purpose of ears is to receive and transmit sound information to the brain. All ears have a dynamic functioning range but if sounds are excessively loud, it may harm the auditory system whereas those that are too low in intensity are simply not processed. One-third of canine population suffers from noise aversion. Dogs are frequently startled by loud noises like gunshots, thunder, or fireworks. Research indicates that some dog breeds are significantly less likely to experience loud noise phobia. Older dogs are more prone to react emotionally negatively to loud noises. Extreme phobic reactions can result from a single traumatic encounter as well as recurrent exposure to frightful stimuli. While phobic responses might include panic, acute agitation, and/or destructive activity, mild fear responses can include panting, pacing and hiding attempts. Sudden, loud noises are one of the most common triggers for fearful behaviours in dogs and many companion dogs suffer from noise sensitivity. This review deals with physiology of canine ear, breed differences in hearing capacities, frequencies of sound that affect dogs and the physiological and behavioural responses of dogs to noise stress. The effect of music on canine welfare and strategies for noise abetment is also elucidated. To protect the wellbeing of dogs and to limit the emergence of anxiety-related behavioural stress issues, a better understanding of interpreting canine responses to noise is imperative.

Efficacy of Souroubea-Platanus Dietary Supplement Containing Triterpenes in Beagle Dogs Using a Thunderstorm Noise-Induced Model of Fear and Anxiety.

A novel botanical dietary supplement, formulated as a chewable tablet containing a defined mixture of Souroubea spp. vine and Platanus spp. Bark, was tested as a canine anxiolytic for thunderstorm noise-induced stress (noise aversion). The tablet contained five highly stable triterpenes and delivered 10 mg of the active ingredient betulinic acid (BA) for an intended 1 mg/kg dose in a 10 kg dog. BA in tablets was stable for 30 months in storage at 23 °C. Efficacy of the tablets in reducing anxiety in dogs was assessed in a blinded, placebo-controlled study by recording changes in blood cortisol levels and measures of behavioral activity in response to recorded intermittent thunder. Sixty beagles were assigned into groups receiving: placebo, 0.5×, 1×, 2×, and 4× dose, or the positive control (diazepam), for five days. Reduction in anxiety measures was partially dose-dependent and the 1× dose was effective in reducing inactivity time (p = 0.0111) or increased activity time (p = 0.0299) compared with placebo, indicating a decrease in anxiety response. Cortisol measures also showed a dose-dependent reduction in cortisol in dogs treated with the test tablet.

Evaluation of Pexion® (imepitoin) for treatment of storm anxiety in dogs: A randomised, double-blind, placebo-controlled trial.

While often grouped with other noise aversions, fearful behaviour during storms is considered more complex than noise aversion alone. The objective here was to assess the effect of imepitoin for the treatment of storm anxiety in dogs. In this double-blind, placebo-controlled randomised study, eligible dogs completed a baseline then were randomised to receive either imepitoin (n=30; 30mg/kg BID) or placebo (n=15) for 28 days. During storms, owners rated their dog's intensity for 16 behaviours using a Likert scale. Weekly, owners rated intensity and frequency of these behaviours. Summary scores were compared to baseline and between groups. Imepitoin was significantly superior to placebo in storm logs and weekly surveys for weeks 2 and 4, and in the end-of-study survey. Mild/moderate adverse events were reported in 26 patients (24 active: two placebo); the most frequent adverse event was ataxia. Owners of dogs in the imepitoin group, compared to placebo, were significantly more likely to report that treatment reduced their dogs fear and anxiety during storms (p<0.001) and other noise events (p<0.001). Twice daily administration of imepitoin decreased anxiety scores in dogs with storm anxiety. Future work may evaluate optimal dosage regimens.

Can anxiolytic medications induce long-term improvement in dogs with noise aversion?

Between 30 and 50 per cent of dogs reportedly experience noise aversion.1 Noise aversion is a broad term encompassing a myriad of active and passive behavioural signs of distress –...

Evaluation of repeated dosing of a dexmedetomidine oromucosal gel for treatment of noise aversion in dogs over a series of noise events.

BackgroundNoise aversion is a common behavioural disorder in dogs; affected dogs show fear behaviours in response to noise stimuli. Pharmacological treatment is effective for many dogs; clinical reports suggest anxiolytic treatment lowers the need for treatment over time. We aimed to evaluate the effect of dexmedetomidine oromucosal gel for dogs with noise aversion over a series of noise events. Furthermore, we evaluated burden of care for owners of dogs with noise aversion via questionnaire.MethodsOwners of enrolled dogs completed records for 10 noise events indicating whether their dog received dexmedetomidine gel and pretreatment and post-treatment anxiety scores; adverse events were noted. Owners were queried about burden of care.ResultsTwenty-two client-owned dogs completed recordings for 10 events. Logistic regression results showed a significant effect for time of event with decreased probability of receiving treatment for subsequent events (OR=0.75, P=0.0017). Within an event, significant improvement in anxiety was seen (median improvement 11 points; paired Wilcoxon; P<0.0001). We found overall burden of care was manageable, yet many owners agreed with statements regarding frustration (42 per cent), stress (46 per cent), guilt (42 per cent) and sadness (75 per cent) about their dog’s condition.ConclusionsRepeated use of dexmedetomidine gel for noise events resulted in decreased need for administration. Burden of care is important to discuss with clients.

New Botanical Anxiolytics for Use in Companion Animals and Humans.

As part of our ongoing research into botanical therapies for anxiety disorders, the neotropical vine Souroubea sympetala was chosen for study as a phytochemical discovery strategy focusing on rare Central American plant families. When orally administered to male Sprague-Dawley rats, the crude plant extract, its ethyl acetate fraction, supercritical carbon dioxide fraction, or its isolated triterpenes reduced anxiety and/or fear-related behavior in standardized behavioral models. Pharmacological studies showed that the extracts acted at the benzodiazepine GABAA receptor and reduced corticosterone levels. A preparation containing Souroubea fortified with a second triterpene containing plant, Platanus occidentalis, was shown to be safe in a 28-day feeding trial with beagles at 5 times the intended dose. Subsequent trials with beagles in a thunderstorm model of noise aversion showed that the material reduced anxiety behaviors and cortisol levels in dogs. The formulation has been released for the companion animal market in Canada and the USA under the Trademark "Zentrol." Ongoing research is exploring the use of the material in treatment of anxiety and post-traumatic stress in humans.

Validation of modified open field behaviour as a measure of trait anxiety in the dog

Trait anxiety may be a predisposing factor for anxiety-related behavioural problems in dogs. This study aimed to measure and quantify trait anxiety using novel behavioural paradigms. Diazepam is an anxiolytic drug which can be used to validate behavioural paradigms that are designed to measure anxiety. Greyhound dogs from a Canine Blood Bank were recruited. Dogs were individually tested in two behavioural paradigms, named the modified open field and the unconditioned substrate preference. The modified open field test consisted of a standard open field test of 10min duration, followed by six individual 10kHz 110dB 1-second tones played every 30s, interspersed with continuous white noise played at increasing intensity from 10dB up to 90dB. For one group of dogs, the test was repeated three times, with two weeks between each test. The greyhounds were pre-treated orally with either an empty gel capsule (sham) or 1mg/kg diazepam 90min before the third trial (n=39). A second group was treated 90min before a single naïve exposure to the test (n=24). Video recordings of the trials were analysed using software which tracked the position of the dog over time. Total distance travelled demonstrated a high test-retest repeatability within subjects (Spearman’s r=0.813, 95% CI: 0.67–0.90, P<0.001) and was increased on average in both test-naïve (167.6m, 95% CI: 54.8–280.4, P=0.005) and test-experienced (139.0m, 95% CI: 89.1–189.0, P<0.001) dogs that had been pre-treated with diazepam when compared with sham. A noise tone as a distance-increasing signal over time had a reduced effect on mean midline distance following diazepam pre-treatment when compared with sham in the test-naïve (−0.79, 95% CI: −1.6 to 0.0, P=0.047), but not to the same extent in the test-experienced (−0.47, 95% CI: −1.5 to 0.6, P=0.370) dogs. The unconditioned substrate preference test consisted of a room that had a concrete floor with half the flooring covered with plastic (a floor substrate unfamiliar to the greyhounds). There was little effect of diazepam pre-treatment on preference for the novel plastic floor substrate. This study suggests that the anxiolytic effect of diazepam on dog behaviour may be measured through an increase in exploratory behaviour and a reduction in noise aversion. Furthermore, exploratory behaviour and noise aversion may represent aspects of underlying trait anxiety as these behaviours have reliable test-retest repeatability.

Benefício fornecido pelo uso de aparelhos de amplificação sonora individual em idosos de um programa de saude auditiva de Porto Velho - RO

OBJETIVO: verificar o benefício do aparelho de amplificação sonora individual na população idosa de Porto Velho, Rondônia e região, além de comparar os achados encontrados com o grau da perda auditiva instalada na população estudada. MÉODO: fizeram parte deste estudo 18 idosos com idade entre 60 e 82 anos, portadores de deficiência auditiva neurossensorial de grau leve a moderadamente severo. O benefício foi avaliado por meio do questionário Abbreviated Profile of Hearing Aid Benefit - APHAB, nas condições sem e com prótese auditiva, sendo tal questionário aplicado no momento da adaptação e três meses após a mesma. Para análise das respostas foram consideradas as seguintes subescalas: Facilidade de comunicação, ruído ambiental, ruído reverberante e aversão a sons. O benefício obtido por subescala foi comparado com o grau da perda auditiva de cada sujeito. RESULTADOS: foi verificado benefício nas subescalas facilidade de comunicação, ruído ambiental e ruído reverberante, tendo tal achado apresentado diferença estatisticamente significante. Quanto à relação do benefício com o grau da perda, verificou-se, dentre os sujeitos com perda auditiva simétrica, maior benefício nos que apresentavam perda auditiva neurossensorial de grau moderado, porém dentre os indivíduos com perdas auditivas de graus diferentes, não foi possível verificar relação entre o grau da perda e o benefício obtido pelos mesmos. CONCLUSÃO: houve redução das dificuldades auditivas com o uso da amplificação sonora em ambientes favoráveis, reverberantes e com elevado nível de ruído.

THE ROLE OF NEGATIVE STATEMENTS ON THE SUBJECTIVE EFFECTS OF TRAFFIC NOISE

This study assesses subjective effects of traffic noise and the mediator role that negative statements about the noise and about oneself play. Eighty-four students underwent two 15-minute presentations of high intensity traffic noise, with and without negative statements. The potential effect of the negative statements was enhanced by the use of instructions concerning the expectation of negative noise effects and the credibility of the statements in half the subjects. Level of anxiety, subjective noise aversion and time estimation of the noise were taken. The State Anxiety Inventory and the Profile of Mood States Questionnaire were used as pre- and post-tests. Noise increased anxiety levels, these levels being higher during the Statements condition than during the Noise alone condition. Instructions further increased the effects of these negative statements. Subjects did not adapt to noise. Scores in the questionnaires were significantly higher in the post-test than in the pre-test. Implications of these results are discussed.

Escape from stimulation of the trapezoid body in rats bred for escape from noise

This study shows that electrical stimulation of an auditory pathway, the trapezoid body, can produce escape behavior comparable in rate and pattern to that of the medial lemniscus, raphe nucleus, and spinal tract of the fifth nerve. The rate of escape increased with increases in voltage or frequency for all of these areas. The rate obtained was equal to or higher than that obtained with noise as the aversive stimulus. No differences were apparent between animals selectively bred for high rates and those selected for low rates. This study suggests that earlier reports of negative affect obtained with stimulation of the auditory system may not be due to negative conditioning, but directly to noise aversion. This investigation also extends the number of pathways in which electrical brain stimulation is known to produce escape behavior.

Retention of conditioned noise aversion following medical geniculate lesions in the rat

The importance of upper auditory pathways at the medial geniculate level was examined in relation to behavior maintained by the termination of intense noise. Rats were conditioned to escape white noise by depressing a lever. Experimental animals were then subjected to varying lesions of the medial geniculate nuclei or posterior thalamic region, with or without lesions of the brachium of the inferior colliculus. Destruction of the medial geniculate nuclei or posterior thalamic region bilaterally did not result in loss of the conditioned behavior. More than half of these animals showed significant postoperative behavioral improvements which were rarely matched by the control animals. Postoperative removal of the noise contingencies to responding was followed by behavioral extinction. Lay-off periods up to 40 days or subjection to anesthesia failed to produce any significant behavioral alterations. However, bilateral tympanic destruction produced definite losses in the response to noise. The evidence suggested that geniculocortical connections are not essential to noise aversion. One case with additional midbrain damage supported earlier findings that this region may be more critical for noise aversion. The possibility that reciprocal (efferent) auditory pathway damage could be responsible for the behavioral improvements is discussed.

The stability and control of conditioned noise aversion in the tilt cage.

Twenty-six rats were used to study the development of stable conditioned responding to terminate white noise (100 or 105 db) in a tilt cage apparatus. Preliminary work, with one end of the cage consistently associated with silence, demonstrated stability at a high level of cumulative noise-off time per session. Time spent at the noise-off cage end was unaffected by lay-off and showed adaptation to reversal of the cage end functions. Variability in reversal acquisition, insensitivity to stimulus intensity changes and persistence in remaining at one end of the cage in the absence of noise-termination contingencies indicated the need for more precise behavioral control. A schedule programming several reversals of the no-noise end at variable intervals within each session was developed. Performance on the latter schedule was characterized by stability of high noise-off times and also proved more sensitive than the preliminary method to stimulus intensity changes (55, 70, 100 db) as measured by both cumulated noise-off time and cage crossing rates. The ease of training combined with sensitivity to stimulus change and the lack of highly specific motor response requirements make this technique promising for use with animals potentially debilitated by drugs or surgical after-effects.

Cerebral structures involved in transmission and elaboration of noxious stimulation.

Cerebral structures involved in transmission and elaboration of noxious stimulation.

Unit activity in reticular formation and nearby structures.

Unit activity in reticular formation and nearby structures.