Perceived acoustic environments, or soundscapes, of intensive care units (ICUs) can be stressful for patients. We developed an approach to enhance ICU soundscapes with soundscape interventions. Compositions of Natural, Human, or Technological sounds were designed to establish three types of sonic ambiances: Comfortable, Pleasurable, or Stimulating. The objective was to investigate the approach's effectiveness in a real-world ICU environment. In a controlled experiment conducted in a single-patient, sound-proofed ICU room, 26 healthy participants were exposed to simulated ICU soundscapes, including patient monitor alarm sounds and mechanical ventilator sounds. Nine soundscape interventions were played via speakers. Perceived pleasantness and eventfulness of resulting soundscapes and experienced pleasure and arousal of listeners were evaluated with questionnaires. Physiological indicators of stress were measured using electrocardiograms (ECGs). Pleasurable and Stimulating interventions significantly increased perceived pleasantness and eventfulness when introduced to the simulated ICU soundscape. Comfortable interventions had no significant effect, suggesting that Pleasurable and Stimulating ambiances better aligned with participants’ needs relative to the simulated soundscape. It emphasized the need to tailor ICU interventions to the preexisting acoustic environment and sound-related needs of listeners, such as comfort, distraction or reassurance. Participants reported positive emotional states while listening to the soundscape interventions, indicative of positive listener experiences. Preliminary insights regarding changes in heartrate variability hinted that soundscape interventions could potentially contribute to reduced stress levels. The effectiveness of interventions depended on their featured sound categories, highlighting the importance of personalization. Overall, our approach was found effective, showing promise for creating listener-centric, restorative soundscapes during ICU stays.

Aims
The sound environment, or soundscape, of intensive care units (ICUs) can be stressful for patients. Soundscapes are defined as acoustic environments as perceived by people. Single-patient rooms mitigate noise, but may deprive patients of essential auditory cues. This might harm basic psychological needs, such as safety. Experiences, needs and emotions regarding soundscapes of single-patient ICU rooms remain unexplored. We aimed to understand how patients experienced these soundscapes.

Methods
This mixed-methods, single-center study involved semi-structured interviews and questionnaires five days after ICU discharge. Patients experienced the soundscapes during their ICU stay, shared experiences in interviews, and selected one to rate on need fulfilment (with a researcher-developed questionnaire), and emotions (with a validated questionnaire). Using thematic analysis, we analyzed interview transcripts by labelling sound-related experiences, sounds, and emotions.

Findings
We interviewed 26 patients. We labelled 259 sound-related experiences, 264 sounds, and 281 emotions, from which six themes emerged: Orientation through sound; Coping with disruptions; Human auditory presence; Monotony and variation; Associations and hallucinations; Communication behind closed doors. Eight patient-selected experiences involved positive emotions. Need fulfilment scores varied: scores were low for communication-related experiences, but relatively high for those involving human presence.

Conclusions
Our findings demonstrated that experiences with single-patient ICU room soundscapes can be positive or negative. For future implementation of such rooms, three insights merit consideration: positive sounds originating from corridors may be unnecessarily removed; alarms in single-patient rooms serve key supportive functions for patients; there is a lack of accessible and appropriate auditory stimulation. We recommend that these insights are taken into consideration to ensure more positive and restorative ICU stays.

Implications for Clinical Practice
In ICUs, balanced approaches that consider both positive and negative aspects of soundscapes may benefit patients in future interventions for noise mitigation. Diversifying the variety of sounds inside patient rooms could further support well-being.