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Airbag Deployment and Hearing Loss
LEnERS TO THE EDITOR Airbag Deployment and Hearing Loss To the Editor: It has come to our attention that noise levels associated with airbag deployment may result in occupants experiencing irreversible hearing loss. Laboratory studies have established the likelihood that an airbag peak acoustic pressure of 170 dB will induce harmful inner ear effects. I In these airbag studies the greatest hearing loss was seen in the inboard ear at 4000 Hz. I have now seen this pattern in patients exposed to airbag deployment acoustics (Tables 1 and 2). These patients showed the greatest hearing loss in the range of 3000 to 6000 Hz. Because the loss occurs above the speech frequency range of 500 to 6000 Hz, it may not be immediately apparent to a patient. Therefore audiology testing is used to detect the loss. The injury to the ear, however, may show up as a ringing in the ear, or tinnitus, which some of the patients did report. Tinnitus is commonly caused by damage to the inner ear and is usually associated with frequencies above the speech frequency range. Thus airbag deployment not only may cause hearing deficits but also may result in the onset of tinnitus. After initial evaluation and management of more serious injuries after an automobile accident, patients who were
exposed to airbag deployment acoustics reported ear difficulties including hearing loss and tinnitus (Table 1). The patients denied any preaccident ear difficulties. Patient 1, a 36-yearold woman, was evaluated for the possibility of ear injury 4 months after an automobile accident. One week after the accident, she noticed a ringing sound and a sensation of stuffiness in her right ear. A week later she noticed some hearing difficulty in the right ear. An audiology test demonstrated a mild, sensorineural hearing loss in the right ear. Patient 2, a 24-yearold woman, was seen for posttraumatic dizziness after an automobile accident. She had no family history of balance disorders. On physical examination, both ears appeared normal. She denied any hearing loss or tinnitus. However, audiology testing showed mild hearing loss in the left ear, especially in the range of 3000 to 6000 Hz. Patient 3, a 40-year-old man, was seen 7 months after an automobile accident for the possibility of a hearing deficit. He had sustained a minor chin abrasion from the accident but had no unconsciousness, vertigo, disorientation, or other signs of brain injury. Because he had no evidence of preaccident hearing loss, the patient appeared to have sustained a postaccident high-frequency hearing loss in his left ear.
.
Table 1. Postaccident audiology tests showing hearing loss
Patient 1 Right Left Patient 2t Right Left Patient 3 t Right Left
250 Hz
500 Hz
1000 Hz
1500 Hz
2000 Hz
3000 Hz
4000 Hz
6000 Hz
8000 Hz
25 10
30 0
35 10
25 10
20 5
30 10
25 10
40 5
25 15
5 5
5 5
5 5
0 5
10 15
5 20
0 10
10 5
5 5
5 5
5 5
0 0
35
0 55
10 55
'Values reflect unmasked air conduction measurements in the right and left ears and are expressed in decibels. tMissing data.
Table 2. Preaccident and postaccident audiology tests showing hearing loss
Patient 4 Right Before After Left Before After
.
250 Hz
500 Hz
1000 Hz
1500 Hz
2000 Hz
3000 Hz
4000 Hz
6000 Hz
8000 Hz
10 20
10 20
10 15
15 20
15 25
30 35
40 55
40 55
55 60
15 15
20 20
15 20
20 25
20 35
30 50
50 65
65 65
65 65
'Values reflect unmasked air conduction measurements in tbe right and left ears before and after airbag deployment and are expressed in decibels.
165
166
OfolaryngologyHead and Neck Surgery July 1999
LETTERS TO THE EDITOR
Establishing a cause-and-effect relationship between airbag noise exposure and hearing loss is possible when an accident involves a patient who has undergone preaccident audiology testing (Table 2). Patient 4, a 73-year-old woman with known, bilateral, sensorineural hearing loss, was in a minor automobile accident in which a single airbag was deployed. Two months later, she was seen for the possibility of ear injury. The patient reported loudness intolerance and an increase in the mild tinnitus she had previously with her sensorineural hearing loss. Physical examination revealed no tympanic membrane abnormalities, and antiinflammatory medication provided no relief. Postaccident audiology testing showed increased hearing loss of more than 10 dB, especially in the range of 3000 to 6000 Hz. In clinical audiology, a 5-dB change is considered a normal variation, whereas a change of more than 10 dB is considered significant. Physicians, other health care professionals, and emergency department staffs should be cognizant of the possibility of yet another morbidity associated with airbag deployment. Patients seen after motor vehicle accidents should be queried about airbag exposure and any noticeable change in hearing or onset of tinnitus. Michael S. Morris, MD, FACS Clinical Associate Professor Department of Otolaryngology-1/Gorman Georgetown University Medical Center Washington, DC 20007 Leticia P. Borja Georgetown University School of Medicine 23/8/98315
REFERENCE I. Price OR. Hearing hazard from the noise of air bag deployment [abstract]. J Acoust Soc Am 1996;4:2462.
Automobile Airbag Impulse Noise To the Editor: I read with great interest the article "Automobile Airbag Impulse Noise: Otologic Symptoms in Six Patients" by Saunders et al (1998;118:228-234). I agree that it is important for otolaryngologists to be aware of the possibility of otologic symptoms produced by airbag deployment. However, some of the information passed on in this article will no doubt serve as ammunition for personal injury attorneys. I firmly believe that there should be a statistically significant change in a patient's audiogram before he or she can qualify as having a hearing loss that might be the result of airbag inflation. Also, some of the "soft" vestibular findings in the patients mentioned in this article who claimed to have dizziness do not provide substantive information regarding vestibular injury. I am currently treating 2 patients in my practice who claim to have hearing loss, dizziness, and tinnitus after automobile accidents in which the airbag deployed. Neither of these
patients have significant changes in their audiometric thresholds. Their only symptoms are those of subjective tinnitus and subjective dizziness. Both are involved in litigation, and I am concerned that this article will be quickly picked up by their personal injury attorneys and waved in front of a jury. Although I agree with the authors that it is important to disseminate information regarding the potential effects of airbag deployment, I believe that we have a greater responsibility to consider the implications of such information, especially when it revolves around subjective symptoms. I would be interested in hearing from the authors how many of these particular patients have litigation pending that might be the cause of their persistent subjective findings. James E. Benecke Jr, MD, FACS Otology & Neurotology 3009 N Ballas Rd, Suite 208 St Louis, MO 63131 23/8/97995
Note: The authors were given an opportunity to respond.
Sudden Hearing Loss and the Need for Immediate Referral To the Editor: I would like to inform my colleagues of a problem that I see with increasing frequency. This is regarding patients with sudden hearing loss who are seen by their urgent care physicians and do not receive referral to ear, nose, and throat specialists for many, many months. Typically, patients have sudden hearing loss in one ear and go to the urgent care center, where they are given antibiotics or eardrops and told to see their regular physician in 2 or 3 weeks. As a rule, they see their treating physician, who prescribes another antibiotic, decongestant, and so forth, and asks them to return in several weeks. Depending on the "culture" of the managed care situation, it may be months before they eventually see an ear specialist. When they finally do see the ear specialist, they are told that the doctor must write to the managed care gatekeeper to get authorization for a hearing test! By the time the final diagnosis is confirmed, it is too late to help these patients. We must educate our friends that when they see sudden hearing loss without obvious evidence of infection, fluid, and so forth, this is as much of an emergency as sudden blindness. I can well remember that in the days before managed care these patients were sent to me that afternoon or early the next day or that evening. Today I see patients with sudden hearing loss 6 months after the event because they are still trying to see an ear, nose, and throat doctor under managed care and have given up. What is even more distressing is that these cases occur right here in Los Angeles, where the expert ear care is so readily available! A partial solution would be for us to teach our friends
exposed to airbag deployment acoustics reported ear difficulties including hearing loss and tinnitus (Table 1). The patients denied any preaccident ear difficulties. Patient 1, a 36-yearold woman, was evaluated for the possibility of ear injury 4 months after an automobile accident. One week after the accident, she noticed a ringing sound and a sensation of stuffiness in her right ear. A week later she noticed some hearing difficulty in the right ear. An audiology test demonstrated a mild, sensorineural hearing loss in the right ear. Patient 2, a 24-yearold woman, was seen for posttraumatic dizziness after an automobile accident. She had no family history of balance disorders. On physical examination, both ears appeared normal. She denied any hearing loss or tinnitus. However, audiology testing showed mild hearing loss in the left ear, especially in the range of 3000 to 6000 Hz. Patient 3, a 40-year-old man, was seen 7 months after an automobile accident for the possibility of a hearing deficit. He had sustained a minor chin abrasion from the accident but had no unconsciousness, vertigo, disorientation, or other signs of brain injury. Because he had no evidence of preaccident hearing loss, the patient appeared to have sustained a postaccident high-frequency hearing loss in his left ear.
.
Table 1. Postaccident audiology tests showing hearing loss
Patient 1 Right Left Patient 2t Right Left Patient 3 t Right Left
250 Hz
500 Hz
1000 Hz
1500 Hz
2000 Hz
3000 Hz
4000 Hz
6000 Hz
8000 Hz
25 10
30 0
35 10
25 10
20 5
30 10
25 10
40 5
25 15
5 5
5 5
5 5
0 5
10 15
5 20
0 10
10 5
5 5
5 5
5 5
0 0
35
0 55
10 55
'Values reflect unmasked air conduction measurements in the right and left ears and are expressed in decibels. tMissing data.
Table 2. Preaccident and postaccident audiology tests showing hearing loss
Patient 4 Right Before After Left Before After
.
250 Hz
500 Hz
1000 Hz
1500 Hz
2000 Hz
3000 Hz
4000 Hz
6000 Hz
8000 Hz
10 20
10 20
10 15
15 20
15 25
30 35
40 55
40 55
55 60
15 15
20 20
15 20
20 25
20 35
30 50
50 65
65 65
65 65
'Values reflect unmasked air conduction measurements in tbe right and left ears before and after airbag deployment and are expressed in decibels.
165
166
OfolaryngologyHead and Neck Surgery July 1999
LETTERS TO THE EDITOR
Establishing a cause-and-effect relationship between airbag noise exposure and hearing loss is possible when an accident involves a patient who has undergone preaccident audiology testing (Table 2). Patient 4, a 73-year-old woman with known, bilateral, sensorineural hearing loss, was in a minor automobile accident in which a single airbag was deployed. Two months later, she was seen for the possibility of ear injury. The patient reported loudness intolerance and an increase in the mild tinnitus she had previously with her sensorineural hearing loss. Physical examination revealed no tympanic membrane abnormalities, and antiinflammatory medication provided no relief. Postaccident audiology testing showed increased hearing loss of more than 10 dB, especially in the range of 3000 to 6000 Hz. In clinical audiology, a 5-dB change is considered a normal variation, whereas a change of more than 10 dB is considered significant. Physicians, other health care professionals, and emergency department staffs should be cognizant of the possibility of yet another morbidity associated with airbag deployment. Patients seen after motor vehicle accidents should be queried about airbag exposure and any noticeable change in hearing or onset of tinnitus. Michael S. Morris, MD, FACS Clinical Associate Professor Department of Otolaryngology-1/Gorman Georgetown University Medical Center Washington, DC 20007 Leticia P. Borja Georgetown University School of Medicine 23/8/98315
REFERENCE I. Price OR. Hearing hazard from the noise of air bag deployment [abstract]. J Acoust Soc Am 1996;4:2462.
Automobile Airbag Impulse Noise To the Editor: I read with great interest the article "Automobile Airbag Impulse Noise: Otologic Symptoms in Six Patients" by Saunders et al (1998;118:228-234). I agree that it is important for otolaryngologists to be aware of the possibility of otologic symptoms produced by airbag deployment. However, some of the information passed on in this article will no doubt serve as ammunition for personal injury attorneys. I firmly believe that there should be a statistically significant change in a patient's audiogram before he or she can qualify as having a hearing loss that might be the result of airbag inflation. Also, some of the "soft" vestibular findings in the patients mentioned in this article who claimed to have dizziness do not provide substantive information regarding vestibular injury. I am currently treating 2 patients in my practice who claim to have hearing loss, dizziness, and tinnitus after automobile accidents in which the airbag deployed. Neither of these
patients have significant changes in their audiometric thresholds. Their only symptoms are those of subjective tinnitus and subjective dizziness. Both are involved in litigation, and I am concerned that this article will be quickly picked up by their personal injury attorneys and waved in front of a jury. Although I agree with the authors that it is important to disseminate information regarding the potential effects of airbag deployment, I believe that we have a greater responsibility to consider the implications of such information, especially when it revolves around subjective symptoms. I would be interested in hearing from the authors how many of these particular patients have litigation pending that might be the cause of their persistent subjective findings. James E. Benecke Jr, MD, FACS Otology & Neurotology 3009 N Ballas Rd, Suite 208 St Louis, MO 63131 23/8/97995
Note: The authors were given an opportunity to respond.
Sudden Hearing Loss and the Need for Immediate Referral To the Editor: I would like to inform my colleagues of a problem that I see with increasing frequency. This is regarding patients with sudden hearing loss who are seen by their urgent care physicians and do not receive referral to ear, nose, and throat specialists for many, many months. Typically, patients have sudden hearing loss in one ear and go to the urgent care center, where they are given antibiotics or eardrops and told to see their regular physician in 2 or 3 weeks. As a rule, they see their treating physician, who prescribes another antibiotic, decongestant, and so forth, and asks them to return in several weeks. Depending on the "culture" of the managed care situation, it may be months before they eventually see an ear specialist. When they finally do see the ear specialist, they are told that the doctor must write to the managed care gatekeeper to get authorization for a hearing test! By the time the final diagnosis is confirmed, it is too late to help these patients. We must educate our friends that when they see sudden hearing loss without obvious evidence of infection, fluid, and so forth, this is as much of an emergency as sudden blindness. I can well remember that in the days before managed care these patients were sent to me that afternoon or early the next day or that evening. Today I see patients with sudden hearing loss 6 months after the event because they are still trying to see an ear, nose, and throat doctor under managed care and have given up. What is even more distressing is that these cases occur right here in Los Angeles, where the expert ear care is so readily available! A partial solution would be for us to teach our friends