Parents: You want your baby to sleep soundly so that you can sleep too, right?
So maybe you bought a machine that will play soothing sounds in the nursery. And maybe you crank up the volume so that your kid doesn't hear sirens outside or household noises.
But how loud should these machines be? How long should you keep them running? Should you put them close to your baby's ears, or on the other side of the room?
A new study in the journal Pediatrics suggests that some noise machines have the ability to produce sounds so loud that they exceed safe levels for adults, let alone infants, and therefore could potentially damage infants' hearing and hinder auditory development.
However, it's important to note that the goal of the study was to measure the maximum effective output levels - not to observe direct effects on children. Experts disagree on what recommendations should be given on using these machines.
"These machines are capable of delivering enough of a dose over a period of time to theoretically cause hearing loss, but that's not been tested," said the study's senior author Dr. Blake Papsin, who is affiliated with the University of Toronto and the Hospital for Sick Children in Toronto.
Researchers tested 14 infant sleep machines at maximum volume, analyzing the noise level production from distances of 30, 100 and 200 centimeters. The 30-centimeter measurement resembles a typical distance from a baby's head to the crib rail; 100 centimeters would be near a crib and 200 centimeters would be across the room from a crib.
The particular machines are not named in the study, but researchers said they are "widely available in the United States and Canada." Papsin declined to reveal which products were used.
These machines play a total of 65 different sounds, including white noise, "nature" sounds, mechanical sounds and heartbeat sounds.
Hospital nurseries and neonatal intensive care units have set a noise equivalent of 50 decibels on average over the course of an hour, according to the study. Canadian and U.S. occupational health and safety authorities have recommended a workplace limit of 85 decibels over eight hours for adults.
Three of the infant sleep machines in this study had outputs greater than 85 decibels, which exceeds that recommendation. Additionally, if these sound devices were played continuously for an eight-hour period, the researchers wrote, "infants would be exposed to sound pressure levels that exceed occupational noise limits" for that time period for adults.
The study authors recommend manufacturers be required to limit maximum sound output levels of such machines, print warnings about noise-induced hearing loss on the packaging and include a timer that would shut the device off after a given period.
They also recommend families place these infant sound machines as far away as possible from the infant - never on the crib rail or in the crib, the study said. The machines should be played at a low volume and for a short time, study authors say.
But wait a minute! Don't we want unwanted noises blocked from infants' ears all night long?
Dr. Harvey Karp, pediatrician and author of books including "The Happiest Baby on the Block" and "The Happiest Baby Guide to Great Sleep," says he has concerns about some of the study's conclusions.
It's true that intensity of sound is important to consider, he said. Concretely, parents should look to make these machines as loud as "a soft shower," he said, and keep them at least a foot (30 centimeters) away from the child's head.
But as far as only using an infant sleep machine for a short time, that recommendation is misinformed and is" not supported by the data in the study," he said.
Karp instead recommends keeping the noise going for the entire duration of sleep, because otherwise the baby will have more disturbances in the middle of the night.
"The white noise is there as a continual presence, just like a teddy bear," Karp said. "It's like a teddy bear of sounds."
Papsin stands by the opposite recommendation in the study, saying that using infant sleep machines over eight-hour stretches is not supported by scientific evidence.
Karp points out the Pediatrics study did not directly address this question with data, nor does it give an overall assessment of risk. Papsin and colleagues were not able to give an estimate of how those risks would weigh against the benefits of the noise devices, either.
The Juvenile Products Manufacturers Association, a trade organization representing manufacturers of 95% of prenatal to preschool products, responded to the study in a statement: "JPMA encourages parents to follow manufacturer guidance and instructions, and to use products as designed and intended. The safety and care of children is JPMA's highest priority."
So what's a parent supposed to do?
There just hasn't been a lot of research into this question of what effect these infant noise machines have, says Patti Martin, director of speech pathology at Arkansas Children's Hospital.
Her bottom line: The issue with the machines is how loud they are, not the amount of time they are used. She also likes the idea of keeping the machines out of the crib because closer noises sound louder to the developing auditory system.
An infant's ear canal is smaller than an adult's, so in babies higher-frequency sounds are amplified, the study said. Evidence from animal studies suggests that risk for age-relating hearing loss may result from early exposure to noise.
Low-pitched, rumbly sounds are better for a baby's sleep, Karp says, as they are "reminiscent of the experience in the womb." Exposing the infant to very loud sounds in short spurts is fine - a baby's own cry is 10 times louder than a hair dryer! - but for promoting sleep, he says, aim for softer and lower-pitched.
Of course, there are other ways to soothe your child to sleep, such as swaddling or holding a baby close, Martin says.
No one knows the long-term implications of masking environmental sounds in infants, in terms of how they will learn later in a noisy environment, Martin says.
On the other hand, a good night's sleep for baby is critical for the health of both parent and child.
"From a safety issue, from a nutrition issue, from a growth issue, all of those sorts of things - sleep is critical for them," she says. "There will always be a group of babies that require a little extra something."
A Salmonella outbreak linked to a California poultry producer has sickened nearly 300 people in 18 states, health officials say. As of Tuesday morning, no recall had been issued.
Raw chicken products from Foster Farms plants have been identified as the likely source of this outbreak of Salmonella Heidelberg.
The CDC first alerted FSIS to a growing number of Salmonella cases on July 1, USDA spokesman Aaron Lavallee told CNN. At the time, 18 people had been sickened in four states, and Foster Farms was a possible link between the patients. USDA investigators began "site sampling," or testing Foster Farms facilities on September 9, and concluded their analysis of the majority of the samples collected on October 7.
"The partial government shutdown did not affect the investigation or communication with the public," Lavallee said.
The Salmonella outbreak comes one week after CDC Director Tom Frieden tweeted: "CDC had to furlough 8,754 people. They protected you yesterday, can't tomorrow. Microbes/other treats didn't shut down. We are less safe."
That raises the question: With government agencies like the CDC on furlough due to the partial government shutdown, is our food supply safe?
The shutdown notice issued by the USDA indicates the the FSIS will continue to inspect birds and animals intended for use as food both before and after slaughter, supervise the further processing of meat and poultry products, ensure that meat, poultry and egg products are safe and also prevent the sale of adulterated meat or poultry products. Despite furloughing 1,218 employees, the USDA says no meat and poultry inspectors have been put on leave.
But future outbreak investigations could be affected by the government shutdown if it continues much longer, some experts say.
"The CDC is the central coordination point and often the leader of the investigation, and the state health departments all collaborate under the umbrella of CDC guidance," says Dr. William Schaffner, chairman of the department of preventive medicine at Vanderbilt University. "The CDC invariably is the conductor of the investigative orchestra."
The game of chicken failed. Neither side blinked. Now millions will pay the price.
Americans watched a colossal failure by Congress overnight - and the shut down of their government.
For weeks, the House and the Senate blamed and bickered, each claiming they're standing up for what the public wants.
In the end, it led to the one outcome nobody wanted - one that will stop 800,000 Americans from getting paid and could cost the economy about $1 billion a week.
This is the first time the government has shut down in nearly 18 years. The last time it did, the stalemate lasted 21 days.
But the largely polarizing Affordable Care Act is funded, and it’s government operations that screech to a halt. CNN's Brianna Keilar reports on Day 1 of the closure.
Telling your kids about being diagnosed with cancer is no easy task.
“Early Start” anchor Zoraida Sambolin was faced with that difficult task when she was diagnosed with breast cancer, and underwent a double mastectomy in May.
Sambolin says, “The first thought I had when I was diagnosed with cancer was this, ‘How will I tell my kids?’”
She has two children she had to break the news to: Nico, 14, and Sofia, 10.
“Once he knew, my son became one of 2.85 million U.S. children sharing their parents' fight against cancer,” Sambolin says.
He reached out to his friends Kyle and Miles for support, and was himself supportive of his mother the entire time.
“Nico's was the last familiar face I saw before surgery,” Sambolin says. “And the first when I came out.”
She caught up with "New Day" to update viewers on her experience thus far. Sambolin says that her prognosis is "excellent" and cancer "has been a blessing."
"When you go back and you look at that and you see your son and you see the suffering that my whole family went through, it's kind of difficult," Sambolin says.
"The road is great. I'm in the middle of reconstruction right now. And that's going really well," She adds. "You know, I've got some decisions to make whether or not I'll go on tamoxifin, it’s an invasive cancer on the left side, so I’ve got to really do a little bit more research and figure out whether that's the next step for me."
Today Sarah Murnaghan begins a brand new chapter in her young life. The 10-year-old Pennsylvania girl received a new set of lungs yesterday in a transplant operation.
Those lungs that came from an adult donor, made possible when the age restrictions for transplants were lifted this week, but only for one year.
Doctors call Sarah's prognosis good. CNN's Jason Carroll is in Philadelphia with the latest.
A scary new warning from the World Health Organization about a virus they say could threaten the entire planet. There are already 49 cases of this new strain of a corona-virus in eight countries. There is no prevention, no cure, and it's killing half the people it infects.
- CNN's Mary Snow reports
READ MORE: Should I be concerned about new virus?
CNN's Senior Medical Correspondent explains new research that could impact our understanding of stem cells. This breakthrough is noteworthy because based on this research these stem cells would be 'genetically identical to you,' says Cohen. This is very important because this way your body will not reject the stem cells.
This new research would allow for samples of an individual’s skin cells to be retrieved, and then turned into an embryo. From this point these embryos would then be made into stem cells. At this point researches are only at the stage where they have taken cells and turned them into embryotic stem cells. However, looking into the future these replicated stem cells could be used to create cardiac muscle, nerve cells or bone marrow cells.
These replicated stem cells could be used to help patients with diabetes, Parkinson’s disease, and even Leukemia.
Researchers estimate it could be another five-ten years before this research is complete.
CNN's Nischelle turner on the stunning revelation by Angelina Jolie regarding her preventive double mastectomy. Jolie revealed her decision in a New York Times Op-Ed.
In her op-ed Jolie addresses why she decided to have the preventative double mastectomy, and why it was so important for her to share her story to bring awareness to other women. She states in her op-ed, "I wanted to write this to tell other women that the decision to have a mastectomy was not easy. But it is one I am very happy that I made. My chances of developing breast cancer have dropped from 87 percent to under 5 percent. I can tell my children that they don't need to fear they will lose me to breast cancer."