Interdisciplinary Healing Through Auditory Stimuli for Mental Health
Advisor: Allendoerfer
Internship Location: Remote
I am conducting a research project that investigates whether auditory stimuli can reduce self-reported stress and anxiety while improving physiological indicators of relaxation, specifically heart rate. The goal of this study is to assess the potential of sound-based therapies as an accessible and scalable complement to existing mental health interventions. This project builds on my interest in non-invasive approaches to mental health support and reflects refinements made after my proposal presentation, including a clearer integration of subjective and objective measures.
To complete this project, I will use a dual research mechanism that combines a small-scale clinical trial with survey-based research, supported by library and internet research on prior studies in sound therapy and stress physiology. In the clinical component, participants will be exposed to specific auditory stimuli while physiological data, such as heart rate, are recorded to evaluate objective relaxation responses. In parallel, surveys administered before and after exposure will measure participants’ perceived stress and anxiety levels. By combining experimental data with self-reported responses, this study aims to provide a more comprehensive understanding of the effects of auditory stimuli on stress. The final product will be a formal research paper that analyzes and synthesizes these findings, accompanied by data tables and visualizations illustrating both physiological and survey-based results.
Project Blog
Week 1: Introduction
During the course of my project, I will be researching the potential of auditory stimuli such as music and sound frequencies in improving mental health and well-being. Conversations around mental health are continuing to expand and there is a growing interest in accessible, low-cost interventions that patients can utilize in everyday settings. This project will explore whether structured auditory stimuli can reduce stress and anxiety while working to improve overall mood.
The central question guiding this research is: Can intentional exposure to specific auditory stimuli produce measurable psychological and physiological improvements in individuals experiencing depression or anxiety? During this first week, I have been conducting a comprehensive literature review. I have been examining existing research in neuroscience, music therapy, and stress physiology to understand how sound influences the brain and autonomic nervous system. Early findings suggest that music modulates activity in brain regions associated with emotional regulation (amygdala and prefrontal cortex) while also influencing cortisol levels and heart rate variability (HRV). I have also been reviewing studies which compare passive listening with guided exercises to devise a structured plan to implement the stimuli. This initial research has helped refine my methodology and moving forward, I plan to finalize the experimental design and determine whether clinical collaboration will be possible, while continuing to build a strong theoretical foundation for the project.
If clearance is possible, this study will take place in a clinical environment. I would be working directly with individuals who report high levels of stress, anxiety, or depression. The clinical setting would allow for a specific sample which fits the requirements of the study as well as controlled implementation of auditory sessions. However, because clinical collaboration has not yet been confirmed, the project may instead rely on surveys and more personal experimental sessions conducted with a less specific sample. This alternative approach would allow for diverse participation and analysis across demographics such as age and lifestyle.
Week 2: Methodology Update
This past week I have seen a lot of progress towards my project and its structure. I have created three playlists to use as auditory stimuli in my experiment. Each of the three will represent different types of auditory experiences and different emotional tones. One will provide calm, relaxing music that will help reduce stress. Another will provide emotionally expressive music that will assist in changing a person’s emotional state. The third will contain guided audio elements and ambient sounds that will be helpful in being mindful and present.
It is important that these playlists were created with a number of factors in mind, including the tempo of the music, the instrumentation of the music, and the content of the music. Research has suggested that music with a slower tempo, as well as a steady beat, is associated with the relaxation response in the body, including reduced heart rates and stress levels. In this regard, the music that is included in the calming playlist is chosen based on the tempo and the steady beat of the music. I attempted to incorporate a variety of genres in the playlists so that they were not boring, but rather interesting for the participants.
In addition to this, I have also finalized the methodology for the research. The participants will be required to fill in a questionnaire before listening to any of the playlists. This will help me assess their current state of mind and their stress levels. Later, they will be required to fill in another questionnaire after listening to the playlist. This will help me assess the change in their state of mind. Although the collaboration for the research is yet to be finalized, the current plan is to conduct the research using volunteers as participants. This will help me gain a wider spectrum of participants and also help me gain useful insights into the impact of auditory stimuli on the state of mind in real-life situations.
Along the way, I also learned a few interesting facts about my overall topic that helped guide the process. For instance, it has been shown that people are able to pick the tone of a piece of music in just a few seconds of listening. Another interesting fact is that the tempo of most relaxing music is between 60 and 80 beats per minute, similar to the average resting heart rate. Additionally, it has been found that listening to music that people like releases dopamine, a neurotransmitter associated with pleasure and motivation.
This week has been an important part of the project in that it has taken the idea and turned it into a more defined experiment. The next part of the project will be the start of the testing phase and the collection of data to analyze the results of how different auditory experiences affect moods and stress levels.
Week 3: Surveys and Preliminary Steps to Testing
This past week, I have completed several key components that are essential in order to commence the experimental phase. First and foremost, all 5 of the auditory playlists have now been completed. Each playlist was carefully refined to make sure that they align with their intended purpose, whether it be for relaxation, to affect an emotional state, or to promote mindfulness and presence. I have made the final adjustments to each of the playlists to make sure that they are cohesive, rather than random.
Along with completing the playlists, I have developed a clearly defined sample pool for the study. In order to create sample diversity based on varying ages, I intend to use a sample of volunteer participants who are about 16 to 60 years old. This way, the study can assess the broadest spectrum of responses to auditory stimulus in relation to age/stages of development throughout their respective lifespan. Several factors such as stress perception, emotional regulation and music preferences will likely vary based on age, therefore recruiting participants from different age categories will enhance the study by creating more representative and accurate findings of what would occur within the general population.
A significant achievement this week was completing the pre- and post-assessment survey instruments necessary for assessing the effects of auditory stimulation. The purpose of these surveys is to measure participants' feelings of stress, levels of emotion, and mental state both pre- and post-exposure to the music, enabling direct comparison to identify any potential changes in these areas. To achieve a high level of reliability, I used the State-Trait Anxiety Inventory (STAI) as a benchmark for developing the pre- and post-assessment instruments. Since the STAI is a well-established research and assessment tool for measuring levels of anxiety, it provides a sense of reliability and validity to my instrument development process. Additionally, I included questions developed from my observations for the purpose of better measuring participants' emotional responses immediately following their exposure to the auditory stimulation, such as changes in relaxation, mood, and concentration. I also attempted to make all questions as simple and clear as possible for the purpose of encouraging accurate, conscientious responses. The pre-assessment and post-assessment are focused on parallel development to facilitate consistent data collection processes and facilitate easy comparison. All pre- and post-assessment will have the same format and all data collected from all participants will be collected via the same form to ensure consistency.
The playlists have been finalized, participants have been selected, and assessment tools have been developed, so the project is now progressing from the planning phase to full data collection readiness. The next phase will involve conducting the experiment, gathering responses, and beginning to analyze how different forms of auditory stimulation influence stress and emotional well-being.
Week 4: Starting Initial Testing
I have officially transitioned my project from preparation to active experimentation this last week! After I prepared my playlists and determined my participants, I was able to order the measuring devices that will allow me to collect objective data to compare to data from the surveys for analysis. Specifically, the measuring devices are a heart rate monitor and cortisol measurements. Both of these measuring devices are reliable physiological indicators of stress. My study will provide more information about both the physical and psychological effects of auditory stimulus due to now having both biological and survey measurements to analyze the same participants.
I successfully set up all materials this week and established a clear and consistent protocol for collecting samples, ensuring the times they are collected are relatively the same (before and after listening) to maintain reliability. I also standardized how heart rate is recorded throughout the session. Taking these steps were important to minimize external variability and ensure that the data collected is as accurate and comparable as possible across participants.
After being prepared, I started experimenting by collecting data from the first five participants (ages 17 to 18). This involved completing each stage of the experiment, including administering the survey prior to playlist exposure to establish a baseline, followed by heart rate tracking during the session and cortisol sampling after the experiment to measure post-assessment changes. Despite these being early samples, there are already some trends emerging from these samples.
For example, Participant 1 showed a clear decrease in both subjective and physiological stress after listening to the calming playlist, with heart rate dropping from 85 bpm to 75 bpm and cortisol levels showing a slight decrease. Participant 2 responded most strongly to the mindfulness playlist, reporting increased focus and reduced anxiety, along with a heart rate decrease from 80 bpm to 72 bpm and a moderate reduction in cortisol. Participant 3 showed minimal change in survey responses but still exhibited a small drop in heart rate and a slight decrease in cortisol, suggesting a more subtle physiological response. Finally, Participant 4 experienced a noticeable improvement in mood with the expressive playlist, though their cortisol levels remained relatively stable despite a small decrease in heart rate.
While these findings are preliminary, they suggest that auditory stimuli may influence both perceived stress and underlying biological responses within a relatively similar age group. However, in order to make stronger conclusions, the whole sample group involving different age ranges must be tested. Moving forward, I plan to continue expanding the sample size and refining data collection to better identify patterns and draw more reliable conclusions about the relationship between sound, stress, and emotional well-being.
Week 5: New Updates and Trends from Testing!
This past week, I continued expanding my experiment by adding new participants in the 20–30 age range, allowing me to begin comparing responses across a broader demographic. I maintained the same structured procedure for each trial. This still includes the pre-assessment surveys, controlled playlist exposure, continuous heart rate tracking, and post-assessment surveys along with cortisol sampling. Keeping the process consistent remains essential for ensuring that differences in results are due to participant response rather than experimental inconsistencies.
With this group, the results were noticeably less uniform than the initial 17–18 age group. For example, Participant 5 (age 23) showed almost no physiological change, with heart rate remaining around 76–75 bpm and cortisol levels staying relatively stable, yet they reported feeling slightly calmer and more focused after the mindfulness playlist.
In contrast, Participant 6 (age 27) exhibited a clearer physiological response, with heart rate dropping from 88 bpm to 78 bpm and a measurable decrease in cortisol, but their survey responses reflected only a minor perceived change in stress.
Participant 7 (age 30) responded in a different way not shown by our preexisting data. This participant showed a slight increase in heart rate during the expressive playlist (from 72 bpm to 77 bpm), possibly due to heightened emotional engagement, while still reporting an overall improvement in mood.
Meanwhile, Participant 8 (age 21) demonstrated mixed results, with a small decrease in cortisol but little to no change in heart rate, and only a modest improvement in self-reported relaxation.
While earlier trials might have shown very stable relationships between participants’ physiological and psychological ratings or responses to auditory stimuli, it is now clear that responses to auditory stimuli do not always result in linear trends concerning physiological and psychological change in some participants (e.g., improvements in subjective experience without as much measurable physiological change). Relations between the individual differences among participants and types of audio could be expected to have an effect on the degree of physiological and psychological responses to auditory stimuli. Therefore, it is not unreasonable to assess greater levels of variability between each participant's physiological and psychological responses to auditory stimuli than previously thought.
In general, this week has demonstrated that measuring levels of psychological change is much more complex across different ages than initially believed. I intend to keep testing and consequently increase the sample size of participants in future sessions. A new trend to analyze is whether variations will be recognizable as broad patterns or if they remain highly variable from one individual to another. Each of these variables must be taken into account in order to draw more definitive conclusions about the influence of auditory stimuli on stress and emotional responses.
Week 6: Patterns of Rhythm and Regulation
This past week, I observed one of the most interesting patterns in my experiment so far. During my continued trials, I began to see a pattern develop in individuals who had been exposed to prolonged periods of auditory stimuli. These participants were beginning to exhibit physiological responses that had become increasingly in sync with the beat and tempo of the music playing.
The heart rate and breathing patterns in certain participants appeared to gradually synchronize with beats or rhythmic structures within the playlists. This effect was most noticeable in tracks with steady, repetitive tempos, where participants’ breathing became more regular and their heart rates began to mirror the pacing of the music over time. Unlike earlier observations, where changes were more immediate or inconsistent, this synchronization effect seemed to require sustained exposure before becoming apparent.
What makes this finding particularly significant is that this alignment is often paired with a noticeable reduction in stress indicators. Participants who exhibited this ‘rhythmic synchronization’ tended to show more linear decreases in heart rate and cortisol levels, alongside stronger self-reported feelings of calmness. This suggests that the body may not just passively respond to music, but can actively adapt to it in order to produce measurable physiological changes.
Another important aspect of this finding is that it helps explain some of the variability observed in previous trials, reinforcing the idea that responses to music are not always immediate or linear. Participants who lacked immediate physiological changes might still be responsive to auditory stimuli, but may require longer exposure to reach this synchronized state.
Moving forward, I plan to continue monitoring breathing rate alongside heart rate to better understand this synchronization effect. I also intend to change the playlist order based on the coinciding physiological effects. This will be done by tempo and rhythmic structure to determine whether certain types of auditory stimuli are more effective at inducing this 'syncing' response. For example, playing the energizing playlist first and the wind-down playlist at the end will give a better sense of how the physiological markers change over the duration of the trial. Ultimately, this finding adds a new layer to my investigation by suggesting that the relationship between auditory stimuli and stress reduction may be more dynamic and interactive than initially anticipated.
Week 7: Starting Data Analysis
This past week marked an important transition in my experiment as I began shifting from active data collection to deeper analysis. While I am still finalizing trials with my remaining participants, I started organizing and examining the physiological data collected so far, particularly focusing on heart rate, breathing rate, and cortisol levels over time.
A major goal of mine this week was to identify consistent patterns among all participants as opposed to identifying patterns within each trial on its own. After compiling the data sets together, I then began creating graphs to show how the physiological recordings changed relative to how long participants had been exposed to sound. This has allowed me to visualize trends that were not so easily identifiable during the live trials. An example of this was working to compare the amount of time it took for participants to achieve the “rhythmic synchronisation” state and whether or not there was any relationship between the timing of this event and a reduction in known indicators of stress.
Preliminary analysis suggests that the synchronization effect does not occur at a fixed time point, but instead varies depending on both the individual and the structure of the music. However, once participants reached this synchronized state, their physiological responses tended to follow a more predictable pattern, with gradual and sustained decreases in heart rate and cortisol levels. This reinforces the idea that prolonged exposure plays a key role in producing measurable stress reduction.
Additionally, I have started to group the playlists into categories based on tempo and patterns of rhythm to assess if musical structures create greater synchronization. My initial observations suggest that songs featuring consistent, repetitive beats may result in quicker synchrony of heart/respiratory rates than songs with no regularity or complexity within the melodic composition.
This week I will finalize the data collection process and start to analyse this data through the lens of my experimental design. This includes further refining the order of the playlists and more accurately determining when synchronisation begins for each participant. Completing the remaining trials will support the reliability of these patterns and validate them with a larger number of participants. Overall, this week has been crucial in bridging the gap between observation and interpretation. By beginning the analytical process while still collecting data, I am better positioned to understand not just what is happening, but why these physiological changes occur in response to auditory stimuli.
Week 8: Establishing a Baseline
This week, I shifted my focus toward establishing a more controlled baseline for my experiment by introducing trials with no auditory stimulation. Up until this point, my data has been centered around how participants respond to different types of music, but in order to fully validate those findings, it is necessary to determine if any physiological change occurs in the absence of auditory stimuli.
I conducted a new set of trials in which participants underwent the exact same procedure, including pre-assessment surveys, continuous heart rate monitoring, breathing rate tracking, and post-assessment surveys, but with no auditory stimuli. Maintaining identical conditions across both sets of trials was critical in ensuring that any differences observed were attributed specifically to the presence or absence of auditory stimuli, rather than external variables.
One of the primary goals of these control trials was to establish whether the reductions in stress indicators seen in previous weeks were truly influenced by music, or if they could simply be the result of participants sitting in a calm, low-stimulation environment. By comparing these datasets, I aim to determine whether rhythmic synchronization and associated stress reduction responses are unique to music exposure.
Preliminary observations already suggest some notable differences. While participants in the no-audio condition often exhibited slight decreases in heart rate over time, these changes were generally less consistent and lacked the patterned synchronization that was previously observed during music exposure. Breathing rates also appeared more irregular, and there was less evidence of the gradual alignment seen in earlier trials. Additionally, self-reported measures of calmness did not show the same level of increase as those in the auditory trials.
As I continue analyzing this control data, I will be directly comparing it to the results from my music-based trials to quantify the magnitude of these differences. This comparison will be essential in determining whether stimuli actively drive physiological changes or if they simply enhance effects that would occur naturally over time. By clearly distinguishing between responses with and without auditory stimulation, I can more confidently draw conclusions about the role music plays in influencing stress and physiological regulation.
Week 9: Graphs Galore!
After setting up a controlled baseline last week, this week was focused on taking all the raw data I collected and turning it into structures that are clearer visual representations of the data. Up until now, everything was more numbers and readings, so my goal was to organize it in a way where patterns would start to stand out more clearly and be easier to compare when presented.
I started by breaking everything down into the main variables I’ve been focusing on (heart rate, breathing rate, and self-reported stress levels). Once that was done, I separated the data based on the type of trial, with one group for participants who listened to music and another for those in the no-audio control condition. Doing this made a huge difference, as it allowed me to look at each condition individually without mixing up any results, and I was able to better compare them side by side to analyze trends and key data points.
From there, I moved into creating graphs to visualize how these patterns changed over time. I mostly used line graphs, as they made it simple to track things like heart rate and breathing rate throughout each trial. What stood out quickly was the difference in linear slope between the two conditions. In the music trials, the data felt much smoother and more structured, with participants’ physiological responses gradually aligning over time. In contrast, the no-audio trials looked more random, with spontaneous fluctuations and less consistency between subjects. Seeing that difference visually made the trend much more evident than just looking at raw numbers.
I also started creating summary visuals like averages and ranges to get a better overall sense of what was happening in each condition. This helped me step back and look at the bigger picture instead of just focusing on moment-to-moment changes. These visuals are especially helpful for when I eventually present my findings, since they make the data a lot easier to understand at a glance.
This part of the project solidified how important data organization really is. The way you structure and present your data can completely change how it’s interpreted. Moving forward, I will keep refining these graphs and plan to start doing more detailed statistical comparisons to further measure the differences I’m seeing. This should help me create a more definite conclusion to whether music is actively causing these synchronized physiological responses and reductions in stress, or if it’s just enhancing effects that would happen naturally over time.
Week 10: HRV and the Vagus Nerve
This week, I continued analyzing how age may influence the patterns I’ve been observing in my data. After continuing my analysis, noticeable distinctions emerged between age groups when comparing participants aged 29–60 to those aged 15–28.
For the 29–60 age group, the data showed a much more consistent and linear relationship across the variables I’ve been tracking. Over time, participants in the music condition displayed gradual and predictable changes. Their physiological responses appeared to stabilize and align in a way that suggests a stronger correlation to and more uniform reaction to auditory stimuli.
One key factor that may explain this trend is changes in heart rate reactivity (HRV) with age. As we get older, our baseline heart rate responses to stimuli often become less reactive and more regulated. This can result in smoother, more linear patterns in physiological data, which is consistent with what I observed with this group.
Another important factor to consider is the role of the vagus nerve. The vagus nerve is a major part of the parasympathetic nervous system and is responsible for promoting relaxation and recovery after the body encounters a stressor. Increased vagal activity is associated with a calming effect on the body, helping to lower heart rate and stabilize breathing. Individuals with higher HRV reflect stronger vagal tone and are typically able to respond to stress more efficiently and return to a baseline state more quickly. This may explain why the older age group showed more consistent synchronization in response to music. If vagal regulation is more stable and/or effectively engaged in these individuals, it could lead to more uniform physiological responses over time.
In contrast, the 15–28 age group showed a more varied and less predictable pattern. While there were numerous moments of synchronization, the overall data included more fluctuations and appeared to be more susceptible to random changes. One possible explanation is that vagal tone and HRV are more varied in younger individuals. This could lead to less stable regulation of stress responses, making physiological reactions to music less consistent and more influenced by moment-to-moment changes or external factors. This shift in my findings suggests that age-related differences in autonomic regulation, particularly involving the vagus nerve and heart rate variability, may play a significant role in how individuals respond to auditory stimuli.
I plan to apply more detailed statistical analysis to measure the strength of these correlations and determine whether the differences between age groups are significant. This will help me better understand whether music’s effects on synchronization and stress are universal or more dependent on factors like age, as well as be able to better graphically interpret the data for my presentation.
Week 11: Final Reflection
Hello everyone! This past week, I had the opportunity to present my final senior project during our Senior Project Presentation Showcase. Throughout the presentation, I discussed my research findings, overall trends, and the conclusions I was able to draw from my project. It was incredibly rewarding to share the work I have spent so much time developing over the past several months. Looking ahead, I hope to continue expanding this project by securing a research position at a VA hospital, where I can apply this research to a specific age group and demographic of patients struggling with anxiety. I am excited by the possibility of further exploring how these findings could be used in real clinical settings and contribute to improving patient well-being. Thank you to everyone who took the time to support, encourage, and follow along with my project journey. I truly appreciate all of the kindness and interest shown throughout this process. A special thank you to Mr. Cunningham for being such a wonderful coordinator and for helping make the senior project experience so meaningful. I would also like to sincerely thank my two advisors, Dr. Allendoerfer and Ms. Eva Glasrud, for their guidance, encouragement, and support throughout the course of my senior project. I could not have done it without them!