Instantaneous hearing loss using a pair of Sony MDR-7506 headphones

Question

Hello Sony, I am posting here to inform you of a life changing event which occurred June 5th while I was producing music with my Sony MDR-7506 headphones on my mid 2012 MacBook Pro.  Long story short, after years of listening to music at low volume levels and being proactive about the maximum output of my devices, I was accidently exposed to three very short blasts of 115 dB SPL noise (less than a second of time total) from my headphones which has given me permanent low frequency hearing loss in my left ear, persistent tinnitus and hyperacusis.   I'd like to mention that the documentation which came with the headphones states only the following precaution related to hearing loss:  "Avoid listening with your headphones at so loud a volume that extended play might affect your hearing”.  The documentation says nothing regarding the possibility of instantaneous hearing loss, and I believe this is something that should be mentioned in an effort to keep users informed.  I was not using any speciallized hardware amplifier, only these headphones and an Apple laptop.   I personally experienced about 115dB SPL (both calculated and measured), which caused my hearing loss, but these headphones can go up to 136 dB SPL (caclualted).  Normally the headphones will have a maximum dB SPL (calculated) close to around 120 dB SPL (macbook pro for example), and this is generally considered loud, but not permenantly damaging.  The fact I have had this serious damage done at only 115 dB SPL is an indication that not all ears are made the same, and as such, users should be warned of the possibilities.  In a recent interview with Jeffery Holt, an associate professor of otology at Harvard University, he is quoted saying, “The more we learn about it, the more we realize that the safe levels are actually lower than we thought previously”.   Personally, I believe it's time to incorperate a standard by which both amplifier and receiver will communicate to help better regulate the damge that can be done.  Such a technology would ensure the saftey of the users and eliminate accidents such as these while remaining relatively simple.  Such devices exist for specialized hardware, but there is the intrinsic difficulty in matching the impedences of the receiver and the amplifier.  A small RFID chip in the headphone cable could easily relay this information to the amplifier, which would then adjust the power output to ensure hearing loss does not occur.   Although such a technology would be wonderful, it is likely not very profitable, as most consumers don't really care to think about their hearing and may even prefer to keep the volume at unsafe levels.  So, I am currently only hoping to speak with someone at Sony about these issues, specifically about the possibility of having this warning added to the packaging of the headphones. Thank You 

Answer 1

Hi veita, thank you for bringing your concern to Sony's attention. We apologize for the inconvenience this may have caused you. Kindly PM me your day time phone number and your most convenient time for a call back. Thanks. - Charlie