Carlos Gordoa and Ariani Reyes, along with their minor son, B.G., filed this personal injury action on May 16, 2022.
Plaintiffs alleged that, while wearing his Apple AirPods Pro (1st generation) (“AirPods Pro”), their minor child B.G. experienced a transient, seconds-long exposure to an Amber Alert that apparently caused profound and permanent hearing loss in his right ear.
Plaintiffs’ causation expert, Dr. Yoav Hahn, opined that B.G.’s exposure to the Amber Alert through his AirPods Pro earbud, which was no more than 113.5 decibels, caused an acoustic shock that resulted in a perilymph fistula (“PLF”) and caused B.G.’s hearing loss.
Apple alleged that Hahn, Plaintiffs’ sole causation expert, is not qualified to offer a general causation opinion, did not offer a general causation opinion, and, in any event, did not identify any basis for a general causation opinion.
Otolaryngology Expert Witness
Yoav Hahn is a clinical physician specializing in the fields of otolaryngology and neurotology.
Hahn completed a skull base surgery fellowship at the prestigious Michigan Ear Institute. He is Director of Neurotology/Lateral Skull Base Surgery at Baylor University Medical Center and is Chief of Otolaryngology at Medical City Dallas Hospital.
Discussion by the Court
General Causation
Hahn is Not Qualified to Render a General Causation Opinion
Hahn reached his opinion based on his experience seeing thousands of patients in his years of practice.
The Court held that Hahn is not qualified to provide an opinion as to general hearing loss causation because he has no relevant research or publication experience and has not engaged with the epidemiological data regarding hearing loss. Therefore, issues of general causation—the level of sound capable of causing the injury alleged here—are outside of Hahn’s expertise.
Hahn Does Not Offer a General Causation Opinion
Hahn has not attempted to answer the question of whether a 10-second exposure to noise stimulus of 113.5 decibels or less could cause a sudden profound hearing injury such as B.G.’s.
However, the Court held that Hahn’s opinion did not address whether a 10-second exposure to noise stimulus of 113.5 decibels or less is capable of causing a profound hearing injury such as B.G.’s.
And Plaintiffs cannot rely on Hahn’s differential diagnosis to establish general causation. Differential diagnosis cannot be used “to demonstrate general causation, because it assumes, without proving, that all of the potential causes considered are capable of causing the condition at issue. Indeed differential diagnosis assumes that general causation has been proven for the list of possible causes it eliminates.”
Any General Causation Opinion is Unreliable
The Court held that Hahn did not identify anything other than temporal proximity related to one case (the litigation for which he is being paid) to support an opinion that a short exposure to noise at 113.5 decibels can cause hearing loss such as that suffered by B.G. He did not perform any research. He did not identify any research. And he did not explain why the decades of peer-reviewed research showing hearing loss only occurs at levels exponentially higher than what B.G. experienced is incorrect. In short, there is no basis for Hahn to offer a reliable general causation opinion.
Specific Causation
Hahn’s Specific Causation Opinions are Unreliable
First of all, the Court held that Plaintiffs’ failure to offer evidence as to general causation is fatal to Hahn’s specific causation opinion. It is not that studies regarding noise-related hearing loss did not exist—it is that no study supports Hahn’s theory.
Second, the Court held that Hahn’s differential diagnosis—the predicate for his specific causation opinion—is unreliable. After all, Hahn’s differential diagnosis is based upon his having ruled out a virus as the cause of B.G.’s injury. Basically, Hahn’s reasoning is not scientifically grounded.
He acknowledged many people infected with COVID are asymptomatic. And most critically, he testified there was nothing “physiologically or pathologically” that allowed him to rule out COVID as the cause of B.G.’s hearing loss. He nonetheless ruled out COVID as a possible cause of B.G.’s injuries because B.G. did not have the symptoms “we associate with COVID-19 in the majority of patients…the fevers, the feeling badly.”
Hahn’s exclusion of COVID was not convincing considering the fact that just because someone did not take a COVID test did not mean they could not have had COVID.
Moreover, Hahn’s reliance on the temporal proximity between the Amber Alert and B.G.’s discovery of his injury did not salvage his opinion. That the Amber Alert was a theoretical cause is not enough to scientifically exclude COVID as a cause.
Held
The Court granted Apple’s motion to exclude the testimony of Dr. Yoav Hahn.
Key Takeaway:
The blatant inconsistencies in Hahn’s reasoning render his opinion unreliable: while acknowledging many people with COVID are asymptotic, he nevertheless concluded B.G. could not have had COVID because the medical records do not show he had symptoms. Further, although he acknowledged hearing loss can be a symptom of COVID, he rejected it as a symptom of COVID in B.G without any scientific explanation.
Case Details:
| Case Caption: | Reyes V. Apple, Inc. |
| Docket Number: | 3:22cv2900 |
| Court Name: | United States District Court for the Northern District of California |
| Order Date: | April 28, 2025 |
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