Study: Waterproof Phone Cases Not Sound-Problem Proof

01.19.2021

Sarah Fray AuD’19 demonstrates how, using an audio test box, a cellphone is measured for audio output with and without a waterproof case.

Waterproof smartphone cases can make it more difficult for people with hearing loss to hear phone conversations, according to University of Texas at Dallas researchers.

Dr. Linda Thibodeau, professor of speech, language, and hearing in the School of Behavioral and Brain Sciences, said the problem cannot just be solved by turning up the phone’s volume.

“For people with normal hearing, it might not be that big of a deal,” she said. “But for somebody with a hearing loss, if they have that kind of smartphone case, it could be enough to where they might need a different program in their hearing aid.”

In a study published online Dec. 16, 2020 in Seminars in Hearing, Thibodeau and co-author Sarah Fray AuD’19 found the materials of a protective waterproof case, which covers a phone’s ear-level speaker, can affect the output of the acoustic signal and could reduce speech recognition by as much as 50%.

According to the National Institutes of Health, approximately 15% of American adults age 18 and over report some trouble hearing. A vast majority of them do not use hearing aids.

While people with hearing loss can often direct the audio from a phone call to their hearing aids via Bluetooth, it also is very common for those with reduced hearing to make cellphone calls in the traditional manner. It is these types of calls that are likely to be negatively affected by a waterproof case.

“This issue could result in significant communication problems,” said Fray, an audiologist with the Fort Worth Veterans Affairs Clinic. “Since there are no facial visual cues to supplement phone communication, it is especially important for hearing health care professionals to know the impact of waterproof phone cases and counsel patients accordingly.”

The researchers tested three cellphones — two Apple iPhone 6s devices and a Samsung Galaxy S7 — both in and out of their waterproof cases by placing the various phone/case combinations one at a time in a test box that generates and measures audio signals. For each phone, there was a reduction in output when contained in a waterproof case compared with no case across three sound levels.

“The plastic covering over the speaker reduced the sound getting out of the phone,” Thibodeau said.

The journal article noted that the study was limited, with a small sample size, and should not be generalized to other phone models and to other waterproof smartphone cases. However, the researchers said it was important for people with hearing loss to be aware of the potential sound issues that a waterproof case could cause.

“Those with hearing loss might need to make choices. Perhaps a person would only use a waterproof case when going fishing or might resort to texting when using a waterproof case. It’s important that they know the potential problem and plan ahead,” Thibodeau said.

–Phil Roth