Talking isn't *necessarily* proportionate to language acquisition: my mother-in-law once attested that my husband was extremely quiet until he blurted out a complete sentence (asking about some stranger on the beach) when he was 5. But even if we suppose it were:
"Because the study couldn't capture parents' silent phone use, including reading emails, texting or quietly scrolling through websites or social media, Brushe said they might have underestimated how much screen usage is affecting children."
If the researchers had been able to detect those other minutes of screen time not collected, but the children's language behavior *is* reliably collected, wouldn't that make language loss per minute of screen time go down, not up?
There also seems to be a presumption that screen time is a 1:1 replacement for child conversation, which would probably not be true across all households. (If parents were perfect like that, we wouldn't need this study to begin with.)