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The sound environment in an ICU patient room—a content analysis of sound levels and patient experiences

Originally Published:
Key Point Summary
Key Point Summary Author(s):
Zborowsky, Terri
Key Concepts/Context

This study was a prestudy for the planning and design  of  a  larger  one,  where  the  aim  is  to  investigate the  relationship  between  sound  (objective  and  subjective) and adult intensive care unit (ICU)  delirium  and/or  other  factors. It used sound measurement, behavioral observation, and interview methods. The results provide a good list of sound/noise impact on patients and subsequent ICU design considerations.

This study took place in Sweden.


The study’s two objectives were to  (1)  describe (using  both  descriptive  statistics  and quantitative  content  analysis)  the  noise  environment  in  an  ICU  patient  room  over  1  day; the  patient’s  physical  status  during  the  same  day;  and  early  signs  of  ICU  delirium; and (2) describe (using  qualitative  content  analysis)  patients’  recall  of  the  noise  environment  in  the ICU  patient  room.  


Nineteen patients were recruited using convenience sampling. (The study excluded people with head injury, known hearing impairment, or dementia.) Of the 19 recruited, 6 died or otherwise withdrew from the study, resulting in a final study group of 13 patients. Researchers collected general patient health status data, ICU delirium observations, and sound-level data for each patient over a 24-hour period. Finally, researchers also conducted interviews following ICU discharge.

Data  were  subjected  to  both  qualitative  and quantitative  content  analysis. The study also presented descriptive  analyses  of  demographic  variables, such as age and length  of  stay. Because  of  the  small  sample,  data  were  presented  descriptively  using  nonparametric  statistics  (medians),  except  for the  sound  levels,  which  researchers analyzed using parametric statistics  (means). Level  of  significance  was  set  to  0.05. To analyze  possible  relationships  between  sound  levels  (LAF-max  and  LAeq)  and  number  of  early  signs  of  ICU  delirium,  the study used the Spearman  correlation  test. Researchers used the Statistical  Package  for  the  Social  Sciences  for  Windows  18.00 for  all  analyses. And analyzed  interviews using  qualitative  conventional  manifest  content  analysis and  followed  the  process  of  organizing  and  integrating  texts into  emerging  codes,  subcategories,  and  categories.

Design Implications
This  study  illustrates  the  need  to  improve  the  physical  environment  in  the  ICU  patient  room.It also  indicates  that  intervention  strategies  are  needed, including:• Acoustical  improvements• Lessening  of  noise• Reduction of  the  volumes  of  technical  alarmsHowever, more research is needed  to  describe  and  understand  the  existing  conditions  of  the  ICU  patient  room  and  find  connections between  noise  and  health. 

The  sound levels  in  the  patient  room  were  high,  and  the  LAF  max  levels  exceeded  55  dB 70–90%  of  the  time.  Most  patients  remembered  some  sounds  from  their  stay  in  the  ICU,  and while  many  were  aware  of  the  sounds,  they  were  not  disturbing  by  them. In  this  small  sample,  the researchers found no  statistical  connection  between  early  signs of  ICU  delirium  and  high sound  levels  (LAeq  p  =  0.63,  r  =  −0.15  and  LAmax  p  =  0.99, r  =  −0.004). However,  it  is  not  only high sound levels that  are  a problem  for patients.  Sounds  from neighboring patients  and advanced  medical  treatments  and  technical  equipment  are  experienced  as  disturbing  and  can  create feelings  of  helplessness,  lessening the likelihood of  finding  the peace  and  calm  that  are  necessary  for  recovery  and well-being.

In addition,  interview results  revealed  the  variety  and complexity  of  the  various  sounds  in  an  ICU  patient  room. For example  the same  sound  could  be  experienced  as  disturbing  on  one  occasion  and  safe  and  comforting  on  another, such as, staff chatting. Finally, the results indicate  that  all  sounds  were  experienced  subjectively,  and  that patients  had  both  positive and  negative  experiences  of  the  sound  environment.  


The authors note that the early  signs  of  ICU delirium  protocol,  which  is  under  development,  has  some limitations  in that  it  has  not  yet  been  analyzed  for  validity or  reliability. They also note that some  of  the  signs,  for  example, “no  eye  contact,”  can  be  connected  to  the  sedative  treatment  as  well  as  to  ICU  delirium.  Another weakness  of  the protocol  is  that  it  is  meant  to  administered  by nurses, who may not always have the  time  to  identify  the  signs  and/or  complete  the  protocol.

Reviewer note: This is a pilot study and was done to test various research methods. Findings should be considered similar to a case study.

Design Category
Acoustic Environment
Outcome Category
Patient / resident health outcomes
Environmental Condition Category
Key Point Summary Author(s):
Zborowsky, Terri
Primary Author
Johansson, L.