Last updated, July 2017
Types of Stethoscopes
There are two types of stethoscopes available in the market today. These are the traditional acoustic stethoscope and the electronic stethoscope.
Standard Acoustic Stethoscope
This is the popular stethoscope. Some people refer to it as a traditional stethoscope as it is the pioneer model. The stethoscope transmits sound from the chest piece (a round or oval shaped broad part) through an air filled tube, to your ears.
The chest piece can either consist of a round disk (mostly plastic) called the diaphragm or a hollow part called a bell. When the diaphragm is placed on a patients’ body, vibrations are emitted from the sounds. The vibrations initiate transfer of acoustic waves to the ears through the tubes. The diaphragm is used to transmit high frequency (high pitched) sounds.
The bell, on the other hand, creates waves from vibrations on the patients’ skin and then transmits them to the ears. The bell transmits low frequency sounds like faint heart sounds of infants.
The major problem with the standard stethoscope is that it produces low volume sounds. Although this is not a huge problem for people with normal hearing, medics with hearing loss can find it challenging to use this scope. A lot of improvement has been made on this steth. However, the improvements are not enough to enable physicians with hearing difficulty perform optimally when using it.
The new generation stethoscopes convert acoustic sound waves to electronic sound signals. Therefore, the output sound is not only amplified, but also processed. Unlike traditional acoustic stethoscopes that have a uniform sound mode no matter the brand, the transducer and the quality of electronic scopes sound vary.
Highly advanced electronic stethoscopes can operate as recording devices. Some stethoscopes have a visual or audio input, which is helpful for medics that are hard of hearing. The electronic stethoscopes can also reduce noise and enhance sound signals.
Electronic stethoscopes are also battery operated. The battery makes it possible for these scopes to amplify acoustic sound signals.
Unlike traditional stethoscopes that emit very low sounds, amplified stethoscopes produce greater volume. The technology used on the stethoscopes enables acoustic sounds to be converted into electronic sounds. The stethoscopes amplify body sounds almost 20 times better than normal stethoscopes. All their other functionalities are however similar to those of normal acoustic stethoscopes.
Medics with mild hearing loss or hearing impairment have a greater challenge competing with those with normal hearing. To listen to body sounds and provide proper diagnosis as the others, they need a stethoscope that will cater for their needs. With excellent listening skills and an amplified stethoscope, physicians who are hard of hearing can be confident when studying heart, lung or bowel sounds for diagnosis.
With or without a hearing aid, a traditional stethoscope cannot provide an accurate listen for a physician with hearing impairment. The low sound emitted by non-amplified stethoscopes can be confusing and lead to incorrect diagnosis .
Features of Amplified Stethoscopes
Amplified stethoscopes have a few unique features not found in a traditional stethoscopes. These include:
- Improved audio clarity
Because they have been designed to produce electronic sounds instead of acoustic sounds, the sounds are clearer and louder.
- Noise reduction feature
The ear tips of the amplified devices are tighter and decrease outside noise. The chest piece is made of an excellent seal material that ensures only body sounds are picked by the diaphragm or bell.
- Headphone use
If you are extremely hard of hearing and have a hearing aid or device, you can use the amplified stethoscopes with headphones.
Using Stethoscopes with Hearing Instruments
A cochlear implant or hearing aid can make it difficult to use an electronic or acoustic stethoscope. If you use these hearing instruments, you will need to use stethoscopes with headphones or stethomate tips.
If you have hearing difficulties and wear a hearing instrument, get a good stethoscope before purchasing stethomate tips.
Stethomate tips are earpiece adapters that come in different sizes and rigidity. Choose tips that fit your ear canal well and can be replaced with the ear tips on the stethoscope.
Challenges When Using Stethomate Tips
Stethomate adapters interfere with the outer surface of your hearing instruments. Apart from this, you may experience the following challenges with them:
- The stethomate tips will prevent your hearing aid from picking up stethoscope sounds if the microphone is too close to the faceplates outer edge.
- The stethoscope tip has fit over the microphone of the hearing device.
- Pressure from the spring loaded earpiece can create painful pressure in your ears, especially since the cochlear or hearing aid is custom made to fit perfectly in the ear canal.
For the above reasons, stethomate tips can only just be used as a backup plan when one has a hearing aid because of their many limitations.
Custom hearing devices are also another option for physicians with hearing difficulties. Different medical equipment manufacturers provide headphones that can be used with stethoscopes. When you use these headphones, the earpieces are unlikely to fall off.
There are two major types of stethoscope headphones; traditional and convertible headphones.
These work with almost all types of cochlear implants and hearing instruments.
These also work with most types of hearing instruments. They are designed to be worn behind the head.
Some people opt for oversized stethoscope headphones. The only mishap with this is that you won’t fully optimize the output sounds from the electronic stethoscope because the signals should pass through the hearing aid first. And hearing aids are not so good when it comes to reproducing certain bass and frequency.
Guide to Buying an Amplified Stethoscope
There are different types of electronic stethoscopes in the market. Examples include fetal stethoscopes that detect fetal heart sound waves and Doppler stethoscopes that detect other organ sound waves.
With the wide variety of amplified electronic stethoscopes from brands like the Littmann, Cardionics, ADC, E-Scope and Thinklabs, it can be challenging choosing the right steth for your needs. Follow the tips below when choosing a stethoscope.
Amplification is measured in comparison to sound from a standard quality acoustic stethoscope. Therefore, consider your specific hearing loss when choosing an amplified stethoscope. You can get amplification of up to 50x with high end stethoscopes and about 16x with low-end amplified steths.
Some amplified stethoscopes allow you to turn the amplification on or off. Others have a volume adjustment knob. This option may be available separately or incorporated in the model switch of the stethoscopes. When incorporated, turning up the amplification will also increase the volume. You may like this option more as it means fewer variables.
Amplified steths are more expensive than their acoustic types. Even if you purchase a basic electronic steth, you will part with more money than you would have with acoustic stethoscope. Most electronic stethoscopes are sold for between $150 and $350.
- Noise reduction
There are electronic stethoscopes with noise reduction optimization. These work like noise cancelling ear plugs or headphones and filter out noise from the surrounding. If you have hearing difficulty, this will help you hear breathing sounds more clearly even when working in a noisy place.
- Power supply
You will not be able to work with your electronic steth if you don’t have batteries. The battery could be lithium, AA or AAA rechargeable. Some stethoscopes give an audio signal when the power is getting low while others have a visual indicator.
Generally, durability of a stethoscope determines its price. If you want a long-lasting stethoscope, invest generously. Read reviews to ascertain the durability of the model you wish to buy. Tubes with wires and that are made of easy bend materials have a short life span.
Consider the weight of the stethoscope model you are purchasing. Some stethoscope like the R.A Bock cardiology dual head are heavy while there are those that are as light as 118 grams.
- Extra features
Most stethoscope manufactures keep up with technological advancements. You will find steths capable of recording and transmitting digital output. Others allow recorded sound to be shared to other electronic devices like smartphones. You can also buy a steth with visualization software.
Buy the Best Amplified Stethoscope
Investing in a good quality steth will help you be confident with your diagnosis every time. With the invention of the amplified electronic stethoscope, medics with hearing difficulties can make accurate diagnosis.