Article

The potential beneficial effect of classical music on heart rate variability in dogs used in veterinary training

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Abstract

Heart rate variability (HRV), the variability between subsequent heart beats, is a measure of autonomic tone, influenced by psychophysiological factors, neurohormonal mechanisms and cardiac disease. Auditory stimulation, specifically classical music, has been documented to benefit well-being in a number of animal species. The aim of this study was to determine whether exposure to classical music improved HRV in dogs used in training during veterinary education for practical laboratories teaching canine clinical examination skills. Sixteen dogs, institutional kenneled dogs and student-owned dogs, were recruited in a cross-over study with a seven-day washout period. Dogs were fitted with a Polar® wearlink strap and HRV data were collected using a Polar® RS800CX human heart rate monitor attached to the dog's collar during the procedure. There were significant differences (P value < 0.05) in HRV indices between dogs exposed to as compared with those not exposed to classical music, specifically the mean RR interval decreased by 6% from 588 to 551 (P value = 0.0072). The standard deviation of RR interval (STDRR) was significantly more variable, 89 versus 109, in the dogs exposed to music (P value = 0.01) and the RR triangulation index (RRTI) increased from 13 to 16 (P value = 0.008). One limitation of this study included small sample size. Different genres and type of music and their effect on HRV of dogs and other animals in veterinary training (and other) settings need to be explored in the future.

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... Fewer studies examined health and/or physiological measures. Three studies examined heart rate variability, with all three finding significant changes with exposure to music [12,17,20]. Two studies examined circulating cortisol concentrations, with one finding no difference in salivary cortisol concentrations as a result of exposure to classical music [12], and the other finding increased urinary cortisol concentrations with exposure to soft rock music [17]. ...
... Overall, classical music was associated with dogs spending more time sitting or lying down, resting and sleeping, and less time vocalizing and standing (Table 1). However, music marketed as being specifically designed for dogs (the five studies examining dog music all used "Through a dog's ear") did not appear to have many beneficial effects over and above those gained by exposing dogs to a random selection of classical music [14][15][16]18,20]. This is likely due to the heterogeneity of the populations studied, and/or a lack of sensitivity in the response variables measured. ...
... Exposure to classical music has been shown to enhance immune function and anti-tumor responses in laboratory rodents (both mice and rats) [21], and immunity and developmental stability in layer chicks [23]. Investigations into the effects of the exposure of veterinary patients to music in clinics have begun [16,18,20], but such studies have thus far been limited by small sample sizes. Another potential use of music in animal shelters is to influence animal movement patterns [8,24] by drawing towards certain areas and repelling them from others. ...
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Music therapy yields many positive health outcomes in humans, but the effects of music on the health and welfare of nonhuman animals vary greatly with the type of music played, the ethology of the species, and the personality and learning history of individual animals. One context in which music therapy may be used to enhance animal welfare is to alleviate stress in domestic environments. Here, we review studies of the effects of music exposure on dogs as a case study for the implementation of music therapy in veterinary medicine. Nine reports of experimental testing for the therapeutic effects of music on dogs were found, with most of these studies focusing on changes in behavior. Overall, exposure to classical music appears to have a calming influence on dogs in stressful environments, with no additional benefit observed from any music purposely designed for dogs (specifically "Through a dog's ear"). Given the cost effectiveness and ease of implementation, music therapy holds promise in veterinary medicine and animal welfare. However, to address precise research questions, further studies must use clearly defined characteristics of stimulus music in the experimental design, and consider the variability of each individual animal's physical characteristics and past experience in the selection of candidates.
... They consisted of a wearlink strap, a watch-computer and a wireless integrated network device. The Polar ® RS800CX has been validated for measuring heart rate variability of dogs [69][70][71][72] and employed in studies using music as environmental enrichment [9,47,73]. The Polar ® V800 has been validated for measuring heart rate variability in humans [74]. ...
... Consequently, an increase in this parameter is thought to indicate a decrease in sympathetic activity. Previous studies have found higher SD2 in dogs exposed to classical music compared to a silence control [9,73]. Bowman et al. [9] interpreted it as a decrease in sympathetic activity, associated to decreased anxiety in the dogs. ...
... No significant differences between enrichment groups were found in RMSSD, pNN50 or LF/HF ratio. Köster et al. [73] did not find significant effects in RMSSD and pNN50 in dogs exposed to classical music compared to those in a silent control during a canine clinical examination practice. In that study, dogs exposed to music had higher SDNN, but lower mean RR than dogs in the control, possibly indicating that exposure to music was a novel experience rather than calming. ...
Article
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Animal shelters can be stressful environments and time in care may affect individual dogs in negative ways, so it is important to try to reduce stress and arousal levels to improve welfare and chance of adoption. A key element of the stress response is the activation of the autonomic nervous system (ANS), and a non-invasive tool to measure this activity is heart rate variability (HRV). Physiologically, stress and arousal result in the production of corticosteroids, increased heart rate and decreased HRV. Environmental enrichment can help to reduce arousal related behaviours in dogs and this study focused on sensory environmental enrichment using olfactory and auditory stimuli with shelter dogs. The aim was to determine if these stimuli have a physiological effect on dogs and if this could be detected through HRV. Sixty dogs were allocated to one of three stimuli groups: lavender, dog appeasing pheromone and music or a control group, and usable heart rate variability data were obtained from 34 dogs. Stimuli were applied for 3 h a day on five consecutive days, with HRV recorded for 4 h (treatment period + 1 h post-treatment) on the 5th and last day of exposure to the stimuli by a Polar® heart rate monitor attached to the dog’s chest. HRV results suggest that music activates both branches of the ANS, which may be useful to relieve both the stress and boredom in shelter environments.
... HRV has been shown to be an effective tool to measure the sympathetic and parasympathetic balance of the ANS (van Ravenswaaij-Arts, 1993;Thayer et al., 2010). HRV reflects variance in time intervals in successive heartbeats, indicating the organism's capacity to regulate internal and external demands (van Ravenswaaij-Arts, 1993;Jarczok et al., 2015;Mccraty and Shaffer, 2015;Shaffer and Ginsberg, 2017 Assessing canine emotional states by implementing HRV indices has been gaining research popularity in recent years (Bergamasco et al., 2010;Gácsi et al., 2013;Bowman et al., 2015;Katayama et al., 2016;Travain et al., 2016;Zupan et al., 2016;McGowan et al., 2018;Köster et al., 2019). It has been proposed that HRV parameters might be sensitive indicators of emotional Nonlinear measures SD1 ms 2 Poincaré plot representing the standard deviation perpendicular to the line of identity (the standard deviation of instantaneous beat-to-beat R-R interval variability) (Tulppo et al., 1996) SD2 ms 2 Poincaré plot representing the standard deviation along the line of identity (the standard deviation of continuous long-term R-R interval variability) (Tulppo et al., 1996) ApEn Approximate entropy, quantifying the regularity and complexity of a time series (Pincus et al., 1991) SampEn Sample entropy estimates the regularity and complexity of a time series (Richman and Moorman, 2000) DFA α1 ...
... Exposure to auditory stimuli in the form of classical music resulted, among others, in mean RR, STDRR, RMSSD, pNN50, SD1, SD2 increase, and LF/HF decrease, indicating parasympathetic nervous system dominance and stressbuffering effects of music on dogs in a stressful environment (Bowman et al., 2015;Köster et al., 2019). Zupan et al. (2016) studied the effects of positive stimuli on cardiac responses in dogs using higher-versus lower-valued food and social reward (familiar and less familiar person). ...
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Although there have been a growing number of studies focusing on dog welfare, the research field concerning dog positive-emotion assessment remains mostly unexplored. This paper aims to provide a state-of-the-art review and summary of the scattered and disperse research on dog positive-emotion assessment. The review notably details the current advancement in dog positive-emotion research, what approaches, measures, methods, and techniques have been implemented so far in emotion perception, processing, and response assessment. Moreover, we propose possible future research directions for short-term emotion as well as longer-term emotional states assessment in dogs. The review ends by identifying and addressing some methodological limitations and by pointing out further methodological research needs.
... 15 The handling of dogs in their puppy period has been shown to have an enduring impact on the hypothalamic-pituitary-adrenal axis, which influences future temperament, capacity for interaction with humans and response to stressful situations. 16 Therefore, dogs that are employed as institutional-owned teaching tools (Köster et al. 2018) or dogs that are habituated to the space used during an investigation (Fukuzawa and Kajino 2018) are at risk of associating certain environments or procedures with a particular outcome or response, otherwise known as conditioning. In the same way, many animals within the general population associate veterinary clinics with an unpleasant experience due to previous visits. ...
... [9][10][11][12][13] Physiological data also showed that classical music significantly lowered heart rate and prompted changes in HRV which indicates parasympathetic nervous system dominance. [11][12][13][14] All six studies concluded that these behavioural and physiological changes represent a lowering of stress levels and inferred that exposure to classical music enhanced the welfare of the study participants. The methodological quality of the studies that were evaluated indicates that a more rigorous research approach to this topic could provide more robust insights. ...
Article
Clinical scenario: Classical music has been extensively studied and acknowledged for its ability to reduce stress and improve patient outcomes in human medicine. It has also been shown to influence the disposition of many captive species within the animal kingdom. Some studies have hypothesised that classical music can also benefit dogs, offering the potential to provide a simple and cost-effective method to improve patient outcomes and canine welfare when dogs are placed in unfamiliar and potentially stressful environments. This critical appraisal examines the current evidence available on the use of classical music for the purpose of stress reduction in hospitalised dogs. Clinical bottom line: Based on six experimental studies, there is only weak evidence which demonstrates that exposure to classical music reduces stress in hospitalised dogs undergoing veterinary intervention. However; it was shown that classical music has the ability to significantly influence specific behaviours and physiological parameters that have been associated with the canine stress response such as heart rate variability, level of vocalisation and time spent resting.
... Some dogs may not like the music or have negative associations due to previous experiences, in which case, this could have a negative impact. One study demonstrated that auditory stimulation, in the form of classical music, improved HRV by a reduced RR variability, suggesting the novel music exposure may have had an excitatory rather than a calming effect [70]. Therefore, a more appropriate approach may be to first expose dogs to a particular type of music in a familiar and relaxing environment before they are subjected to a stressful event. ...
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Veterinary visits can be stressful for dogs, but how their wellbeing changes during a visit is not well understood. Music therapy has been successfully used in clinical practice to alleviate stress and anxiety in people. The present study aimed to understand how canine stress changes during a veterinary visit, establish the effect of music, and highlight measures which may be of practical use. In a randomized crossover design, dogs were exposed to no music and a bespoke piece of classical music at a tempo designed to match their resting heart rate during a mock veterinary visit. Dogs were scored as more “afraid” during the physical examination compared to when they were in the hospital kennel (p < 0.001). Salivary cortisol, IgA, and infrared temperature all increased significantly (p < 0.05) from baseline to post-kennel and post-examination, with no effect of music treatment. Core body temperature (p = 0.010) and the odds of ‘relaxed’ lips (p = 0.020) were lower when dogs were exposed to music compared to control visits. Overall, dogs experienced changes in physiology and behavior, indicative of increased stress, over the course of the visit. Additional research is required to further understand the effect that bespoke music may have in alleviating canine stress during veterinary visits.
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In the wild, animals are exposed to an ever-changing array of sensory stimuli. The captive environment, by contrast, is generally much more impoverished in terms of the sensory cues it offers the animals housed within. In a bid to remedy this, and promote better welfare, researchers have started to explore the merits of sensory stimulation (i.e. stimulation designed to trigger one or more of an animal's senses) as a potential method of environmental enrichment for captive animals. This paper reviews the research in this area, focusing specifically on auditory, olfactory and visual methods of sensory stimulation. Studies exploring the efficacy of each type of stimulation as an enrichment tool are described, where appropriate, making a distinction between those that occur in the animal's natural habitat, and those that do not. Overall, it is concluded that sensory stimulation harbours enrichment potential for some animals housed in institutional settings, although the specific merits gained from these enrichments are likely to depend upon a wide variety of factors including, for example, species, sex, age and housing conditions. Programmes of sensory enrichment that target the dominant sense for the species under scrutiny, using harmless, non-stressful stimuli, are likely to result in the greatest benefits for animal welfare. Stimuli specific to a species’ natural habitat should not always be considered meaningful, or advantageous, to an animal's welfare; in some cases stimuli that do not occur naturally in the wild (e.g. classical music) may offer more in the way of welfare advantages. Shortcomings in the research, and factors to consider when implementing enrichment of this nature, are discussed throughout.
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The main objective of this experiment was to assess the effect of music on the voluntary approach of cows to an automatic milking system (AMS). A group of 19 mid- and late-lactating Holstein cows with 2 months prior experience of twice-daily milking in the AMS was used in this study. The cows were housed in a free stall barn with slatted floors and fed a complete mixed ration using an indoor feed bunk. They were also offered 1.5 kg per cow of grain pellets in the AMS during milking. Music was played during the milking period for 69 days prior to observation with amplifiers located within the milking compartments, approximately 1.2 m above the head of the milking cows and also on the long side of the barn. The sounds were activated at the start of each milking period and terminated after the last milking cow left the AMS. Behavioural observations were carried out during the afternoon milking for 20 days randomly fluctuating between days with music and days without music. The number of cows in the holding area was instantaneously recorded at 5 min before and 5 min after the onset of the milking period. On days with music, the number of cows in the holding area increased from 22.3 ± 15.1% to 45.0 ± 18.0% (P < 0.01). On control days without music, this difference was less pronounced, increasing from 27.1 ± 13.7% to 35.1 ± 15.4% (P = 0.150). Changes in the composition of behavioural states from 5 min before to 5 min after the onset of the milking period were significant on days with music (P < 0.001) but not on control days (P = 0.412). The results show a stimulatory effect of music, influencing behavioural readiness of cows to access the milking compartments of the AMS.
Article
This study explored the influence of five types of auditory stimulation (human conversation, classical music, heavy metal music, pop music, and a control) on the behaviour of 50 dogs housed in a rescue shelter. The dogs were exposed to each type of auditory stimulation for 4 h, with an intervening period of one day between conditions. The dogs' position in their kennels (front, back), their activity (moving, standing, sitting, resting, sleeping), and their vocalisation (barking, quiet, other) were recorded over 4 h at 10 min intervals during each condition of auditory stimulation. The dogs' activity and vocalisation were significantly related to auditory stimulation. Dogs spent more time resting and less time standing when classical music was played than when any of the other stimuli were played. Exposure to heavy metal music encouraged dogs to spend significantly more of their time barking than did other types of auditory stimulation. Classical music resulted in dogs spending significantly more of their time quiet than did other types of auditory stimulation. It is suggested that the welfare of sheltered dogs may be enhanced through exposure to appropriate forms of auditory stimulation. Classical music appears particularly beneficial, resulting in activities suggestive of relaxation and behaviours that are considered desirable by potential buyers. This form of music may also appeal to visitors, resulting in enhanced perceptions of the rescue shelter's environment and an increased desire to adopt a dog from such a source.
Article
This study explored the effect of auditory stimulation on the behavior and welfare of four zoo-housed, female Asian elephants ( Elephas maximus). All animals were exposed, in an ABA design, to two conditions of auditory stimulation: a 'control' (no auditory stimulation), and an 'experimental' condition, during which the animals were presented with a commercially-available CD of classical music. Each condition lasted for five days, with an interim period of two days between each condition (Study 1). The elephants' behavior was recorded every minute for four hours a day for the full five days of each condition using instantaneous scan-sampling. The procedure was repeated four months later (Study 2), for a shorter period of time (one day per condition, again using an ABA design) to assess whether the results are generalizable. Analysis of both studies revealed that the elephants spent significantly less of their time stereotyping during the experimental conditions than the control. None of the other behaviors recorded were influenced significantly by auditory stimulation. Overall, the findings from this study suggest that auditory stimulation, in the form of classical music, may be a useful method of reducing stereotypic behavior in zoo-housed Asian elephants, although more long-term work with a larger number of animals is needed before firm conclusions can be drawn. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Article
The physiological reaction to psychological stress, involving the hypothalamic-pituitary-adrenocortical and sympatho-adrenomedullary axes, is well characterized, but its link to cardiovascular disease risk is not well understood. Epidemiological data show that chronic stress predicts the occurrence of coronary heart disease (CHD). Employees who experience work-related stress and individuals who are socially isolated or lonely have an increased risk of a first CHD event. In addition, short-term emotional stress can act as a trigger of cardiac events among individuals with advanced atherosclerosis. A stress-specific coronary syndrome, known as transient left ventricular apical ballooning cardiomyopathy or stress (Takotsubo) cardiomyopathy, also exists. Among patients with CHD, acute psychological stress has been shown to induce transient myocardial ischemia and long-term stress can increase the risk of recurrent CHD events and mortality. Applications of the 'stress concept' (the understanding of stress as a risk factor and the use of stress management) in the clinical settings have been relatively limited, although the importance of stress management is highlighted in European guidelines for cardiovascular disease prevention.
Article
To investigate the prognostic and diagnostic value of heart rate variability (HRV) using the vasovagal tonus index (VVTI) in dogs suffering from idiopathic dilated cardiomyopathy (DCM). Electrocardiographic (ECG) recordings of 369 patients presented to a referral centre between 1993 and 2006 were reviewed. VVTI values were calculated from 132 dogs. Lower VVTI values were found in patients in International Small Animal Cardiac Health Council (ISACHC) heart failure (HF) class 2 and 3 compared with class 1. VVTI was found to be positively correlated with survival time (ST) in class 2 and 3 patients. When a cut-off value of 7.59 for VVTI was used, the test could differentiate patients in ISACHC HF class 1 versus 2 and 3 with a sensitivity of 89 per cent and a specificity of 62.5 per cent. The ST for patients with VVTI values less than 7.59 was significantly lower. The VVTI is a useful index, obtained from a standard ECG recording that estimates HRV in dogs and does not require any specific equipment for its calculation. It can be useful as a diagnostic tool to assess the severity of HF and is a useful prognostic tool in dogs with DCM.
Article
Heart rate variability was measured in 81 Cavalier King Charles spaniels to investigate if it could be used to evaluate the severity of mitral regurgitation and to predict decompensation. Heart rate variability was assessed by the natural logarithm of the variance of the R-R intervals for 20 consecutive beats obtained from electrocardiographic recordings. Twenty-two of the dogs were clinically normal and 59 had mitral regurgitation caused by chronic valvular disease. The severity of mitral regurgitation was evaluated by echocardiography and thoracic radiography. Heart rate variability was found to be reduced (P < 0.001) among dogs with severe left atrial and ventricular dilatation and clinical signs of congestion. No significant differences in heart rate variability were found among normal dogs, dogs with only cardiac murmur, and dogs with echoradiographic evidence of slight to moderate left atrial and ventricular dilatation. Overall, an association was found between heart rate variability and left atrial to aortic root ration and left ventricular end diastolic diameters (r = 0.72 and 0.64, respectively, P < 0.001), as well as heart and respiratory rate (r = 0.80 and 0.69, respectively, P < 0.001). Multiregression analysis showed that, in order of importance, heart rate, left atrial diameter and respiratory rate had significant effects on heart rate variability. Among these parameters, heart rate variability and left atrial diameter were found to be most efficient in separating decompensated dogs from compensated. It is concluded that heart rate variability may provide the clinician with valuable information when assessing the severity of mitral regurgitation caused by chronic valvular disease.
Article
To characterize the salient variables of the time-domain analysis of heart rate variability (HRV) in clinically normal Doberman Pinschers and to compare those variables with those of Doberman Pinschers with cardiomyopathy and mild to moderate myocardial failure. 46 Doberman Pinschers. HRV was analyzed in the time-domain from 24-hour Holter recordings obtained from 28 Doberman Pinschers with normal echocardiograms and 18 Doberman Pinschers with echocardiograms consistent with mild to moderate myocardial failure. Significant differences in HRV variables between the 2 groups of dogs were not detected. The HRV was greater during the nighttime (12 AM to 6 AM), compared with the 24-hour day and an 18-hour (6 AM to 12 AM) period. HRV of dogs with mild to moderate myocardial failure was not different from that of clinically normal dogs, because there were no disturbances of autonomic balance, baroreceptor function, and other factors that influence HRV in the dogs with cardiomyopathy, or the sensitivity of time-domain analysis was overwhelmed by normal sinus arrhythmia. The techniques now used to study HRV have important limitations, especially in dogs, and better noninvasive tests of autonomic function are needed.
Article
This study examined the prevalence of behaviour problems exhibited by dogs within 4 weeks of acquisition from a rescue shelter in Northern Ireland. One thousand five hundred and forty-seven people who had purchased a dog from a rescue shelter in Northern Ireland were sent a postal questionnaire designed to collect information on the behaviours exhibited by their dog within the first month of acquisition. Five hundred and fifty-six people responded to the survey, representing a response rate of 37%. The majority of respondents (68.3%) reported that their dog exhibited a behaviour problem, the most common being fearfulness. Most of those respondents (89.7%) who returned their dog to the shelter did so because the animal exhibited behaviour that they considered undesirable. Male dogs showed more unacceptable behaviours than females, specifically inter-male aggression, sexual problems and straying tendencies. More stray dogs displayed undesirable behaviour than unwanteds, specifically straying tendencies. Puppies were less likely to exhibit unacceptable behaviours than juveniles or adults, particularly fearfulness, sexual problems and straying tendencies. More juvenile dogs showed excessive activity and excessive barking than puppies or adults. More adult dogs displayed aggression towards other dogs than juveniles or puppies. Findings indicate that dogs purchased from rescue shelters do exhibit behaviour problems that may lead to their return. The number of dogs admitted or returned to rescue shelters with behaviour problems may be reduced by raising public awareness regarding the value of behaviour therapy and introducing behaviour therapy schemes to rescue shelters.
Article
The vasovagal tonus index (VVTI), a time-domain indicator of heart rate variability, was measured in 92 dogs of six breeds (German shepherd dogs, labrador retrievers, cocker spaniels, boxers, bulldogs and cavalier King Charles spaniels). There was a significant difference in VVTI between the six breeds (P = 0.003). Brachycephalic dogs had a higher VVTI than other types of dog (P < 0.005), and when comparing individual breeds brachycephalic breeds tended to have a higher VVTI than non-brachycephalic breeds, although the difference was not always significant. The VVTI was negatively correlated with heart rate (P < 0.01) and dogs suffering from congestive heart failure had a lower VVTI than other dogs, whether compared within or between breeds (P < 0.01).
Article
Little information is available about the effect of music on the operating room (OR) staff. The objective of this study was to evaluate the perception of the influence of music on physicians and nurses working in the OR. A questionnaire was designed and 250 copies were distributed to the doctors and nurses working in the OR at three hospitals. One hundred and seventy-one returned the completed questionnaire and were included in this study. 63% of the participants listen to music on a regular basis in the OR. Classical music is the most requested (58%) and most of the responders do not choose the type of music according to the type of the procedure. In our study, the nurses were more likely to listen to music and the willingness is higher among the female responders. The desired volume is lower as age increases and 78.9% of the participants claimed that music in the OR makes them calmer and more efficient. According to our study, music has a positive effect on the staff working in the operating rooms.
Article
Is music just noise, and thus potentially harmful to laboratory animals, or can it have a beneficial effect? Research addressing this question has generated mixed results, perhaps because of the different types and styles of music used across various studies. The purpose of this study was to test the effects of 2 different types (vocal versus instrumental) and 2 genres (classical vocal versus 'easy-listening' vocal) of music on social behavior in 31 female and 26 male chimpanzees (Pan troglodytes). Results indicated that instrumental music was more effective at increasing affiliative behavior in both male and female chimpanzees, whereas vocal music was more effective at decreasing agonistic behavior. A comparison of 2 genre of vocal music indicated that easy-listening (slower tempo) vocal music was more effective at decreasing agonistic behavior in male chimpanzees than classical (faster tempo) vocal music. Agonistic behavior in females remained low (<0.5%) throughout the study and was unaffected by music. These results indicate that, like humans, captive chimpanzees react differently to various types and genres of music. The reactions varied depending on both the sex of the subject and the type of social behavior examined. Management programs should consider both type and genre when implementing a musical enrichment program for nonhuman primates.
Bioacoustic research and development 340 canine research summary
  • J Leeds
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Stress and Disease (Sprinfield, Ilinois)
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Heart rate variability: Standards of measurement, physiological interpretation, and 344 clinical use
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