How many months children lose the ability to distinguish sounds that are not part of the household language?

Children typically begin to lose the ability to distinguish sounds not present in their household language around 6 to 12 months of age. This process, known as perceptual narrowing, allows them to focus on the phonetic distinctions relevant to their native language. By about 12 months, most infants have significantly reduced their ability to differentiate sounds from languages they are not exposed to.