As explained, heart sounds in particular are lower frequency than most speech sounds. Even as low as 20Hz. Like hearing aids, headphones are designed to reproduce speech clearly. They’re also designed for music so may have a better low frequency response than hearing aids. Even so, many headphones don’t perform well enough at the very low frequencies and won’t reproduce some heart sounds. So it is essential you check the specifications of any headphones you buy.
Cardionics supplies headphones to use with their E-scope and Vi-scope stethoscopes, so these can be relied on to have a good low-frequency response. I have a Cardionics E-scope supplied with two types of Koss headphones. The basic headphones appear to be Koss ktxpro1 on-ear headphones. The headband is a bit too long for some of us and the headphones slip down. The “convertible” style, Koss sporta pro on-ear headphones, can be adjusted smaller and worn either over or behind the head. Cardionics also supply full size headphones, the Koss UR40 lightweight headphones, that some people with BTEs find more comfortable and that will reduce some background noise. For very noisy situations such as in ambulances, helicopters and even noisy emergency departments, Cardionics supply an amplified stethoscope with aviation-style headphones.
Koss details the specifications on their website so you can compare these with other headphones. Cardionics tests each set before supplying them but I don’t know how much variability there is and therefore whether we can rely on buying the same model from another (non-medical) supplier. Or other makes with similar specifications. (If someone has more information, please let me know. Thanks.)
Thinklabs also have information about headphones, here.
If the headphone plug doesn’t match the stethoscope output socket (for example the Thinklabs stethoscope has a 2.5mm socket) you can buy an adapter . Depending on quality, this may attenuate the signal. You may need a higher quality adapter or to rewire the plug.
- Have you read the essential safety information: “limitations of hearing aids and implants?”
- Consider funding
- Arrange a trial period
- And see how your audiogram matches up to heart and lung sounds to find out whether you need amplification or not.
- Don’t forget, hearing aids don’t usually reproduce the low frequencies well. So if you’re using earpieces, custom moulds or headphones over hearing aids you also need vents in your ear moulds or open fitting.
Which stethoscope? Comparison chart.