As you may already know, the SI unit for frequency is Hertz (Hz); an event that repeats once per second has a frequency of 1 Hz. According to most sources, the human hearing (frequency) range is between 20 Hz and 20,000 Hz (bats can hear up to 100,000 Hz!).
Note: Some jurisdictions have laws requiring passengers on bicycles to be at least one year old. Usually by age 12 months parents can start checking with the child's physician to see if they have the neck development to safely go for a bike ride.elevance. Rating Newest Oldest. Best Answer: Obviously a child can't be on a bike until they can safely wear a helmet. http://www.helmets.org/little1s.htm Nobody we have met in the injury prevention field recommends taking an infant of less than 12 months in a bicycle child seat, trailer, sidecar or any other carrier.
However, parents of individual babies are in the best position to decide when their baby has the physical ability to ride in an umbrella stroller safely. Some infants may have no difficulty when they are as young as 4 months, while others may not be ready to sit up well until they are 7 or even 8 months old. If you are not sure whether your infant is developmentally ready for this type of stroller, then seek your paediatricians opinion.