1. A computer implemented method for detecting a change in a home environment for a visually impaired user, the method comprising: mapping, using a sonar mapping system, a first sonar map of a set of areas of the home environment; mapping, in response to receiving a noise alert from a sound detection system coupled to the sonar mapping system, a second sonar map of the set of areas; identifying an object of the second sonar map meeting an obstruction criterion; and providing a notification to the visually impaired user that the identified object meets the obstruction criterion, in response to an alert from a sleep sensor.