Nature Sounds Without Words: A Four-Week Audiovisual Program Eased Student Anxiety and Depression

A quiet revolution in digital mental health is being built not from words, but from waves, forests, and candlelight. A research team led by Yi Qin of the Shanghai Conservatory of Music and Feng Chen of the University of Shanghai for Science and Technology has reported that a four-week, audio-dominant, nonverbal audiovisual program was associated with meaningful reductions in anxiety and depressive symptoms among college students. The study, published in BMC Public Health, compared three groups of students and found that both a wordless version of the program and a narrated version outperformed a waitlist control, with no statistically significant difference between the two active formats. The finding matters because most digital mental health interventions today are built on text, a design choice that may quietly exclude users who struggle with reading, prefer other sensory channels, or live outside the cultural context in which the material was written.

The experiment enrolled 334 eligible college students, who were systematically allocated in chronological order according to a repeating A-B-C sequence rather than random assignment. The completer analysis ultimately included 193 participants: 58 students in Group A, who received the audio-dominant nonverbal audiovisual intervention; 57 students in Group B, who received the same audiovisual materials with guided narration; and 78 students in Group C, a waitlist control. Attrition was substantial and roughly similar across the two active arms: 47.7 percent of Group A and 48.6 percent of Group B were not included in the final analysis, along with 30.4 percent of the control group. Baseline records were available for all 334 allocated participants, but post-intervention scores on the outcome scales were available only for the 193 completers, and the reasons for non-completion were not recorded. The authors were transparent about these limitations, noting that no imputation-based intention-to-treat analysis or missing-outcome sensitivity analysis was performed.

The intervention itself was delivered through a WeChat mini-program, a lightweight application embedded in the messaging platform that dominates daily digital life in China. For four weeks, participants in the active groups engaged daily with 15-minute nature-themed sessions built around four scenarios: Ocean, Forest, Flower Garden, and Candlelight. Group A experienced these scenes in an audio-dominant, nonverbal form, in which sound carries the therapeutic payload and visuals support it without spoken guidance. Group B received the identical materials with guided narration layered on top. This pairing of conditions constitutes what the researchers call a subtraction design: by removing the narration from one arm, they could isolate the contribution of verbal guidance and test whether the nonverbal core of the program stands on its own.

Outcomes were measured with two well-established self-report instruments. The primary outcome was the Self-Rating Anxiety Scale, or SAS, and the secondary outcome was the Self-Rating Depression Scale, or SDS. Both instruments ask respondents to rate a series of symptoms and yield scores that rise with symptom severity. The authors note an important methodological caveat: the hierarchy that placed SAS above SDS was established post hoc, after data collection, rather than being prospectively prespecified. This kind of transparency is increasingly expected in behavioral intervention research, where outcome choices made after the fact can inflate the apparent strength of findings. Here, the consistency of results across both scales offers some reassurance, but the post hoc designation tempers how decisively the hierarchy can be interpreted.

The statistical picture was striking. In the completer analysis, the researchers found significant group-by-time interactions for both SAS and SDS, each with p values below 0.001, indicating that the trajectory of symptom change differed across the three groups. Within-group analyses showed significant post-intervention reductions in both SAS and SDS scores across all three groups, including the waitlist, a reminder that simply being observed and assessed can coincide with symptom improvement. Crucially, both Group A and Group B showed greater symptom reductions and lower adjusted post-test scores than the waitlist control, with all Holm-adjusted p values below 0.001. The Holm procedure is a sequential correction for multiple comparisons, designed to keep the overall risk of false positives in check when many statistical tests are run at once, which strengthens the credibility of the between-group contrasts.

Effect sizes told an equally compelling story. Large within-group pre-post effect sizes were observed in the two active groups, with partial eta-squared values ranging from 0.36 to 0.40. In behavioral science, partial eta-squared values above 0.14 are conventionally considered large, so figures in this range describe changes that are not merely statistically detectable but substantial in magnitude. However, the comparison between the two active arms came back null: no statistically significant difference was detected between the nonverbal and narrated versions for either the anxiety or the depression scale, with both Holm-adjusted p values at 0.434. The authors are careful to state that this null result does not establish equivalence between the two formats. Demonstrating equivalence requires dedicated equivalence testing with pre-specified margins, which this study did not perform. What the result does show is that the wordless version performed at least as well as the narrated one in this sample.

Why would sound-led, nonverbal content help at all? The researchers frame their approach around the hypothesis that nonverbal audiovisual material may impose a lower cognitive load than text-heavy interventions. Reading demands active decoding, working memory, and language proficiency, all of which compete for the same mental resources that are already strained in anxious or depressed states. By shifting the informational burden to ambient natural sound and imagery, the program may allow users to settle into the experience without the friction of comprehension. The team also points to potential cross-cultural generalizability as a motivation: a forest soundscape or the rhythm of ocean waves requires no translation, whereas guided text must be localized for every language and cultural context it reaches. The study’s abbreviation list hints at the acoustic toolkit involved, referencing binaural beats and head-related transfer functions, technologies that shape how spatialized audio is perceived by listeners through headphones.

The institutional collaboration behind the work is itself notable. The author team spans the Department of Music Engineering at the Shanghai Conservatory of Music, psychological education and counseling centers at the University of Shanghai for Science and Technology and the Shanghai Technical Institute of Electronics and Information, the medical psychology teaching and research department of Shanghai Jiao Tong University School of Medicine, and a cultural communication company. This blend of audio engineering expertise and clinical psychology practice reflects a growing recognition that effective digital mental health tools are as much a design and engineering challenge as a clinical one. The work was supported by the Shanghai Education Science Research Project, and the protocol was approved by the relevant institutional bodies with all participants providing informed consent in accordance with the Declaration of Helsinki.

Still, the study’s limitations deserve as much attention as its results. The trial was not prospectively registered, the allocation was systematic rather than random, and nearly half of the participants in the active arms did not complete the post-intervention assessment, with reasons unrecorded. Because the analysis was restricted to completers, the reported effects apply only to students who finished the program, and it is impossible to know from these data whether dropouts differed systematically in ways that inflated the apparent benefit. A waitlist control, moreover, cannot separate the specific effects of the intervention from expectation, attention, or the passage of time. The authors themselves conclude that further confirmatory studies are needed to establish the intervention’s clinical value and to evaluate its proposed cognitive load advantages and cross-cultural generalizability, rather than claiming therapeutic efficacy outright.

Even with those caveats, the study opens an intriguing frontier. If a wordless, 15-minute daily encounter with simulated nature, delivered through an ordinary smartphone, can coincide with large symptom reductions in students who complete it, then the design space for digital mental health support may be far broader than the text-based paradigm that currently dominates the field. The subtraction design used here offers a template for other teams: build the sensory core of an intervention, then systematically add or remove verbal scaffolding to learn what actually does the work. For the millions of students worldwide who report anxiety and depressive symptoms, and for the counselors and technologists trying to reach them, the message of this research is quietly radical. Sometimes the most effective thing an app can say is nothing at all, and simply let the ocean speak.

Subject of Research: A nonverbal, audio-dominant audiovisual intervention for reducing anxiety and depressive symptoms in college students

Article Title: Effects of an audio-dominant nonverbal audiovisual intervention on anxiety and depressive symptoms in college students: a three-arm systematically allocated controlled intervention study

Article References: Effects of an audio-dominant nonverbal audiovisual intervention on anxiety and depressive symptoms in college students: a three-arm systematically allocated controlled intervention study. (n.d.). https://doi.org/10.1186/s12889-026-29647-5

Image Credits: AI Generated

DOI: 10.1186/s12889-026-29647-5

Keywords: digital mental health, college students, anxiety, depression, audiovisual intervention, nonverbal, nature sounds, Self-Rating Anxiety Scale, Self-Rating Depression Scale, WeChat mini-program, controlled trial, cognitive load