*Article* **Sound Perception of Blind Older Adults in Nursing Homes**

**Yue Wu 1,2, Sijia Huo 1,2, Jingyi Mu 1,2,\* and Jian Kang 3,\***


**Abstract:** The number of blind older adults is gradually increasing with the aging of world's population, and their needs and perception of sound are specific. This study investigated the behavioral activities of blind older adults and the dominant sound sources through on-site observation of an allblind nursing home in China, and it used semi-structured interviews to obtain the sound perceptions of blind older adults. The findings showed that the daily behavioral activities can be categorized into basic living activity, leisure activity, social activity; and physical activity. The dominant sound sources included human, equipment, informational, and environmental sounds. This study developed a sound perception model of blind older adults in nursing homes, which takes three levels: sound requirements, acoustic environment, and sound cognition. Firstly, the blind older adults have a basic understanding of sound from the perspective of their living needs, then they feel the sound environment from the perspective of the living environment, and finally, they perceive the acoustic environment from the dimension of sound cognition in conjunction with contextual memory. This study sheds a light on the aural diversity of older adults, which is expected to support the inclusive design of nursing homes for older adults with visual impairments.

**Keywords:** blind older adults; nursing homes; acoustic environment; sound perception; aural diversity; inclusive design

#### **1. Introduction**

With at least 2.2 billion people suffering from vision impairment [1], an estimated 1.8 billion suffering from presbyopia [2], and 196 million having age-related macular degeneration, which is expected to increase to 288 million by 2040 [3], vision impairment along with aging has become a global public-health concern. In addition to congenital anomalies and accidents, the cataract, glaucoma, age-related macular degeneration, diabetic retinopathy, and presbyopia are common causes of vision impairment [4]. The number of people with vision impairment is gradually increasing with the increase of aging population, with 43.3 million people worldwide expected to be blind in 2020 [5].

To address the difficulties that visually impaired or blind people have in mobility [6–10], non-verbal sounds and/or speech, such as musical cues, are often used to convey shapes and figures [11,12], because visually impaired people acquire spatial information through hearing to deal with various challenges, especially in unfamiliar environments [13–15]. Miura et al. examined the mobility situation and mobility needs of visually impaired people and found that they could deal with impairment through acquiring auditory information with various strategies, such as rotating the head to hear environmental sound more clearly, or tapping the floor hard with a cane or foot to enhance reflective or reverberant sounds [16]. However, sound has both positive and negative effects on visually impaired people: footsteps and stick echoes can complement acoustic signals, and certain continuous sounds make orientation easier, while noise can interfere with sounds that

**Citation:** Wu, Y.; Huo, S.; Mu, J.; Kang, J. Sound Perception of Blind Older Adults in Nursing Homes. *Buildings* **2022**, *12*, 1838. https:// doi.org/10.3390/buildings12111838

Academic Editor: Cinzia Buratti

Received: 30 August 2022 Accepted: 20 October 2022 Published: 1 November 2022

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**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

provide directional guidance [17]. Rychtarikova suggested that the known indoor sound sources are preferred by blind people and argued that the acoustic environment could help people to extract unfamiliar indoor space information, while excessive noise affects positioning [18]. In conclusion, the architectural acoustic environment is significant for people with vision impairment.

A poor indoor acoustic environment can not only harm the health of older adults [19–21], but may also hinder their everyday life in nursing homes [22]. Zeng studied the living environment of older adults in different functional rooms in 11 nursing homes in Guangzhou, China, and found that the acoustic setting had the most significant impact on the subjective evaluations of the older adults among all the physical settings of nursing homes [23]. Some studies, however, found that the acoustic quality of the building environment designed for the general population was largely inappropriate for the disabled and the elderly with hearing loss [24]. Other studies also found that the acoustic environment was the second crucial environmental parameter, just after the light, affecting the behavior and health of dementia patients [25], and a good acoustic environment was vital in helping to delay the onset and progression of Alzheimer's disease [26,27].

Soundscape first proposed in 1929 [28] was later defined as the study of the effects of the acoustic environment on the physical responses or behavioral characteristics of creatures living within it [29]. The research on soundscape was gradually applied to the urban and architectural design, and formally introduced in the 16th International Congress on Acoustics [30]. And International standard ISO 12913-1 (2014) defines soundscape as "[the] acoustic environment as perceived or experienced and/or understood by a person or people, in context" [31]. Due to the important progress of soundscape research in both the natural and social sciences in recent years, many studies have explored the understanding and perception of soundscape in urban construction [32–35] and building type [36–40], and investigated the subjective perception of soundscape in specific populations such as children [41,42], the elderly [43,44], and people with disabilities [45,46]. In terms of the soundscape perception of blind people, Rychtarikova used in-depth interviewing with blind adults to understand their experience of the built environment and discussed the issue of the inclusiveness of soundscape [47], and reviewed the studies on topics related to sound and soundscape perception of blind people, and concluded that blind people perceive the reality also in a multisensory way [18]. Mediastika et al. found that the dimension of eventfulness of park soundscape and the dimensions of pleasantness and space of mall soundscape were the most prominent factors and suggested that the visually impaired used hearing to perceive the danger and direction of the soundscape [48,49]. Hearing differences lead to auditory diversity, and researchers have found differences in hearing levels among infants, adolescents, adults and older adults. We do not yet know how blind older adults perceive sound differently from others?

Generally, blind older adults can only choose to stay at home or live with other older adults in nursing homes [50,51], which brings up the needs to study the inconveniences of the environment for blind older adults. This study examined the only nursing home in China that provides the environmental and service support for blind older adults. As shown in Figure 1, this study first investigated the architectural environment and space of the nursing home, then observed the daily behavioral activities of the blind residents in the nursing home, and finally conducted semi-structured interviews with the blind residents on their sound perceptions, aiming to answer two main questions: 1. How do the blind older adults behave and what are the sound sources in nursing homes for them? 2. How do the blind older adults in nursing homes perceive sounds? This study expects to help nursing homes provide the better environmental support for blind older adults.

**Figure 1.** Research framework.

#### **2. Materials and Methods**

#### *2.1. Field Survey*

The all-blind nursing home where the study was conducted is located in Shenyang, Liaoning Province, Northeast China. It has five floors with a total of 96 care units. As shown in Figure 2, the first floor of the building composes of a multifunctional hall, activity rooms, office rooms, and rooms for other purposes, mainly for the daily activities of the blind older adults and the staff, the second to fifth floors of the building are for care units where the blind older adults live. In addition to the rooms for their daily activities, there are other care units for them to engage in social interaction and the corridors for them to stroll during inclement weather. There were about 30 to 50 blind older residents and 12 staff members at the time of study.

(**b**) Third floor plan

**Figure 2.** Floor plan of the nursing home. (Note: ).

Image acquisition is an important research method for observing the behavior of the observed [52–56]. To avoid the collision between the camera and the blind older adults, this study was conducted during the period from 5:00 to 20:00 when the residents were awake [21], on 20 July 2021 and 27 December 2021, with typical summer and winter weathers, respectively. The number and type of activities performed by the blind older adults in the six types of spaces—multifunctional hall, activity room, outdoor space, public circulation, and personal and other care units—were monitored and recorded in the nursing home. In addition, during the two days of the study, the researcher circled the nursing home every hour and recorded the sound sources that could be perceived indoors.

#### *2.2. Field Interviews*

In this study, the semi-structured interviews were conducted with the blind older adults and the staff members living in the nursing home in terms of the sound perception of the nursing home. The interview questions were:

Q1. What do you think of the acoustic environment of the nursing home?

Q2. What are your sound perceptions in the nursing home in your daily life?

Q3. What sounds do you think need to be added to, or subtracted from, the nursing home?

The researchers took down in shorthand in the memos the participants' answers to the questions, and their own findings and reflections; afterwards the memos were transcribed; finally the transcripts were coded and entered into the Nvivo 11 software for analysis.

The definition of blindness was based on the criteria in Chinese National Standard on Disability Classification and Classification of Persons with Disabilities [57]. Two field interviews were conducted on 21 July and 28 December 2021, followed by the two behavior observations on the next days, respectively. And the data from 37 interviews and the basic information of the participants were collected, as shown in Table 1 and Figure 3. In order to not cause psychological stress to the blind older adults and to reduce their vigilance, the researchers were introduced by the nursing workers into the care units, to explain the purpose of the study and obtain the consent of the participants before conducting the interviews. The interviews were relayed and recorded. In accordance with local legislation and institutional requirements, this study was ethically reviewed by the Harbin Institute of Technology. Afterwards, the interview data were coded, induced, and clustered based on classical grounded theory [58–63] to construct a sound perception model of the blind older adults in nursing homes.



**Figure 3.** Age and sex distribution of the respondents.

#### **3. Results**

*3.1. Behavioral activities and Sound Sources*

3.1.1. The Behavioral activities of the Blind Older Adults

As shown in Figure 4, the blind older adults living in the nursing home have a consistent schedule for their activities. They usually wake up one after another at 5:00 a.m. Breakfast is served from 7:30 a.m. to 8:00 a.m. Before breakfast, the blind older adults rest

in their rooms or stroll in the courtyard. In the morning, they may spend time in activity rooms doing activities, such as singing, dancing, massaging, and playing cards, etc., or in their living rooms for entertainments, such as surfing the Internet, listening to songs, news, playing musical instruments, etc., and may also move to others' rooms to gossip together. After lunch, some blind older adults take a walk outside to digest food, while the others rest in their rooms. After a while, the residents nap in their own care units. From 14:30 to 16:30, most of the blind older adults gather in the multifunctional hall for some group activities, such as performing, playing games, and making dumplings, while the others entertain in their own rooms. After dinner, most of the blind older adults choose to walk, work out, or talk outside, while some remain in their rooms. After 19:00, all the residents retreat to their rooms to rest, and most of the blind older adults take their shower in the public shower room. After 20:00, the nursing home is quiet, for the residents fall sleep one after another. In winter, the cold weather reduces the residents' willingness to go outside, so most of them choose to walk back and forth in the corridors for exercise, wake up later in the morning and spend more time in the care units.

**Figure 4.** The daily behavior and space utilization of the blind older adults.

3.1.2. Sound Sources in the Nursing Home

Based on the data about the building layout, site conditions, user behavior, and sound sources in the nursing home, the study categorized four main types of sound sources: human sound, equipment sound, informational sound, and environmental sound. Firstly, the human sound refers to the sound generated by the behavioral activities of the blind older adults, such as talking, walking, and doing activities. Secondly, the equipment sound refers to the sound generated by the equipment and machinery in supporting the normal operation of the nursing home and the recreation of the blind residents. Thirdly, the informational sound refers to the sound generated to signal the movement and activities of the blind older adults, for example, a variety of audible messages set up at key points both indoors and outdoors in the nursing home. Finally, environmental sound refers to the sound in the surroundings of the nursing home, which can be heard inside the nursing home, such as traffic and natural sound. The types of sound sources in the nursing home are shown in Figure 5.

As shown in Figure 5a, the indoor sound sources in the nursing home are:


(**a**)

**Figure 5.** *Cont*.

**Figure 5.** (**a**) Indoor sound sources in the nursing home; (**b**) outdoor sound sources in the nursing home.

Moreover, as shown in Figure 5b, the outdoor sound sources that can be heard indoors in the nursing home are:

