## 2 A Theoretical Model
### Sound Therapy Model for Homesickness  
Music therapy is widely applied in various fields, especially as a component of multimodal therapy in psychiatry [25]. Music therapy in psychiatry adopts a cognitive behavioral approach, addressing patients' needs by stimulating their musical responses. The core mechanism of music therapy is that, first, the patient's target behaviors are evaluated, and the need factors and risk factors are contrasted with the main symptoms. Second, the music therapist creates musical situations to elicit the patient's behavioral and emotional responses. Third, music is employed to induce behavioral changes in the patient. Figure 1 illustrates the treatment cycle used by music therapists in cognitive behavioral music therapy in psychiatry, which is highly effective in altering the behavior of psychiatric patients. The success of the music therapy process depends on the therapist's awareness and utilization of the neurological and physiological effects of music. The essence of music therapy is that the music therapist must select appropriate music to create scenarios \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Sounds Type** & **n** & **Mean** & **Sounds Type** & **n** & **Mean** \\ \hline \multicolumn{5}{c}{Coastal city (\(p\) = 0.001)} \\ \hline City street (e.g., car, bus, bicycle) & 82 & 2.78 & Sound of sea (e.g., waves, wind) & 66 & 2.83 \\ Crowded people in the street & 82 & 2.23 & Seagballs crying & 66 & 2.03 \\ Fireworks & 82 & 2.39 & Firecrackers (e.g., marriage) & 66 & 2.21 \\ Cicadas in summer & 82 & 2.33 & Fireworks & 66 & 2.18 \\ Gentle pet (e.g., cat, dog) & 82 & 2.23 & Cooking food (e.g., meat, hotpot) & 66 & 2.12 \\ Early morning with birdsong & 82 & 2.23 & Gentle pet (e.g., cat, dog) & 66 & 1.89 \\ Cooking food (e.g., meat, hotpot) & 82 & 2.37 & Early morning with birdsong & 66 & 1.94 \\ Cheers (e.g., concert, game) & 82 & 2.16 & Firewood burning & 66 & 1.97 \\ \hline \multicolumn{5}{c}{Generic city (\(p\) < 0.001)} \\ \hline City street (e.g., car, bus, bicycle) & 131 & 3.09 & Sound of rural life (e.g., birdsong) & 44 & 3.09 \\ A tractor working & 131 & 2.20 & Cave (e.g., sound of water drops, echo) & 44 & 1.90 \\ Early morning with birdsong & 131 & 2.46 & Firewood burning & 44 & 2.09 \\ Fireworks & 131 & 3.02 & Wind blowing the leaves & 44 & 2.16 \\ Cooking food (e.g., meat, hotpot) & 131 & 2.50 & Streamlet & 44 & 1.95 \\ Gentle pet (e.g., cat, dog) & 131 & 2.50 & Animal sounds (e.g., dog barking, cow) & 44 & 2.20 \\ Cicadas in summer & 131 & 3.06 & Firecrackers (e.g., marriage) & 44 & 2.27 \\ Passing train & 131 & 2.29 & Cooking food (e.g., meat, hotpot) & 44 & 1.98 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The variance in the different sounds in the four cities. that elicit emotional responses from the patient. The intensity of these responses can be amplified by the neurophysiology arousal responses in the patient's brain [26]. Homesickness is generally considered a psychological condition and belongs to the field of psychiatry. While it can have physical symptoms, such as sleep disturbances or headaches, these are typically secondary to the emotional and mental distress caused by homesickness [27; 2]. Therefore, the core mechanisms of the music therapy model can also be analyzed and applied to homesickness therapy. The first step is to evaluate the personal background and needs of the homesick person to achieve a good effect of sound therapy. The second step is to use sound to create a scene that evokes the person's hometown and memories. Unlike cognitive therapy for psychiatric disorders, homesickness is a common psychological issue, and people can alleviate homesickness and prevent psychological problems through daily self-intervention. Moreover, for the sound selection of homesickness treatment, music is not the only sound component, as there are representative sounds of the hometowns in different regions.