I am not an expert but it might be the problem with microphone or sound processing and not actual noise. For example, my smartphone mic picks up lot of noise from wind even if the wind is not strong, while human's ears somehow reduce or suppress the wind noise.
Also, modern smart speakers use arrays of microphones and medical devices might be using some outdated tech.
Also, modern smart speakers use arrays of microphones and medical devices might be using some outdated tech.