First of all, it is important to understand that imagery is description which appeals to one of the five senses. This means the author paints a picture through sight, smell, taste, sound, or touch. Imagery is not the same thing as figurative language.
One clear picture of sight and sound imagery is used in chapter 4, when Chillingworth pays a personal visit to Hester and the baby in jail. Notice the stark contrast in the description of Chillingworth's quiet demeanor as contrasted with the crying baby who is visibly and outwardly mirroring the inner turmoil of her mother.
Descriptions of Chillingworth:
The stranger had entered the room with the characteristic quietude of the profession to which he announced himself as belonging. Nor did his demeanor change when...left...face to face with the woman (66).
The "characteristic quietude of the profession" is a description of the calm confidence a physician must possess when entering the room of a patient. He conducts himself in a controlled manner, which is starkly contrasted with the out of control state of Hester (inwardly) and her baby (outwardly):
His first care was given to the child; whose cries, indeed, as she lay writhing...made it of peremptory necessity...the task of soothing her (66).
In this chapter, the reader can see and hear a screaming and upset newborn baby, and a mother who is useless to sooth her. Then, we witness a calm and collected doctor enter the room, take control of the situation, and quiet everything down to his level. The imagery here foreshadows Chillingworth's future control over other characters in the story, which he continues to do from a place of quiet and resolute calm, secrecy, and silent control.