I plan on making an appointment with my baby's pediatrician but before I do, I wanted to get some feedback on my concern.
Earlier this evening, while at home, our baby monitor was too loud resulting in feedback "high pitched" noise. Our new born (1 week old) was in the other room and woke up to the noise. That said, what is the DB level on a baby monitor's speaker? Should I be concerned that my child may have suffered hearing loss?
Any answers would help. Thank you.
I wouldn't worry about 10-15 seconds of feedback noise from a monitor when the child wasn't even in the same room. Even if the child was in the same room it wouldn't cause hearing loss as the amount of sound a battery powered speaker can produce isn't nearly enough to cause hearing loss, especially so short a period.
Generally it sounds like you don't have to worry. Did you hear the noise from a similar distance? Can you still hear? The human body is very resiliant. Your child will be exposed to a lot of noise over the course of his first few years, from popping balloons to the sound of his own voice or his brothers and sisters screaming. Don't worry about the minor damage that will occur inevitably due to the environment.
At the same time, you should minimize unnecessary exposure to the baby (e.g. vaccums, squealing baby monitors). Don't give a baby an overinflated balloon or something that might pop.
So like, regarding noise and talking to doctors. If your child does hear a loud noise and experiences mild hearing loss then there is nothing your pediatrician can do about it. Just make sure it doesn't happen in the future.
A pediatrician cannot evaluate or quantify minor hearing damage in a baby. It is unreasonable to ask this.
Also don't use Q-tips or swab your baby's ears. Earwax is a natural defense against loud noise.
Short version: don't worry about it, but don't repeat either.
Long version: Permanent damage is a function of exposure level and exposure time. Legal requirement for a workplace (OSHA) are 85 dBA for 8 hours, 95 dBA for 4 hours, 105 dBA for 2 hours etc. Pain threshold sits at about 115 dBA to 120 dBA. Some clinical studies suggest that these limits are actually on the high side but that's currently the law.
The most common damage is mechanical damage of the receptors in the inner ear (stereocilia in the cochlea for the Latin inclined). Sound waves actually wiggle a membrane in the inner ear and this vibration than wiggles the nerve endings which fire impulses to the brain. Excessive motion wears out the nerve endings and they die.
The limits above are obviously for adults, I'm not aware of studies that assess that for children or infants. However we can assume that a baby's ear is significantly more sensitive since the nerve cells are a lot smaller and hence more fragile. I would estimate at least 10 times more fragile which would mean to deduct 10dBA from those limits. To be really safe I would assume 100 times more sensitive and subtract 20 dBA. So as a general rule a baby should not be exposed to more than 65 dBA for 8 hours. 65dBA is about the level of a loud animated conversation.
[side note: babies have also have different frequency sensitivity curve than adults so the "A" weighting isn't really appropriate but we'll ignore this to keep it simple]
In your particular case, the exposure was very short. It really can't do any damage unless it was significantly above the pain threshold in which case your baby would have probably shown clear signs of discomfort. Also your baby was in a different room and walls and doors are quite good at absorbing high frequency sound. Even if it's ear splitting in the kitchen it's not all that loud in the bedroom.
At high frequencies even a small baby monitors can actually get quite loud, so this is something to watch for and avoid repetition.
On the ear wax: I agree, you should leave that alone and have nature deal with it, simply because there is significant risk to damage the ear drum or the middle ear when poking around in there. Ear wax is absolutely NOT there to protect against loud sounds. If there is so much build up that it actually affects the hearing, you need to have it cleaned out by a doctor.
Finally there is no point in going to a pediatrician since there isn't really anything she can do. I don't know whether you can diagnose anything at all at this age. Even at a few months old you can only check for major hearing problems at best.
No I don't think you should worry about hearing loss, unless it was happening often.
I use a BT monitor which has a dect signal and I don't get any feedback with it. If you are interested to know, here is the one I have: http://www.babymonitorsonline.co.uk/audio-baby-monitors/bt-baby-monitor-250-hd-audio.html
