Age makes a difference on heart rate in any situation. According to wikipedia, the maximum heart rate (HRmax) is the highest heart rate an individual can safely achieve through exercise stress, and depends on age.

In this sense, we can also consider that the hearing ability of a person can vary with age, too. If a person can not hear because of hearing impairment due to an illness or to advanced age, then the effect of music will be different compared to a person whose hearing abilities are normal. We can then conclude that age makes a difference in a person who listens to music and then measures the change in heart rate.