Various devices can be used to conduct pure tone audiometry. These can range from conventional standalone audiometers, smartphone based, computer based and even computer controlled audiometers. With such a variety, confusion is inevitable. Many people can’t distinguish between a computer based and computer controlled audiometer - partly because no one ever talks about it. This results in the interchangeable use of the terms.
Surely a ‘computer based audiometer’ is any audiometer that is or can be connected to a computer? No, these devices are completely different and these distinctions will be highlighted below.One of the main differences is that computer controlled audiometers are calibrated together with their transducers. On the other hand, computer based ones only have their transducers (i.e. supra aural headphones) calibrated. Calibration is imperative to ensure accurate and precise results.
An audiometer is a medical device used to determine the lowest sound level a person can hear (hearing threshold). This will help determine whether the individual has normal hearing or not. Hearing is assessed by presenting tones and having the person indicate by raising their hand or pressing a response button when they hear the tones.
A computer based audiometer uses a sound card with a digital to analog converter. This acts as the pure-tone generator as well as the masking signal generator. The computer simulates a conventional audiometer in order to generate tones presented to the patient without the use of external devices. The audiometric programs are developed based on Microsoft Windows or Apple Macintosh. Clinicians use the computer system as one would utilize any computer application.
What is a PC Based Audiometer?
Computer based, refers to the fact that the audiometer is in fact in the computer, mobile phone or tablet. While some receive broad classification as an audiometer, they are more akin to an audiometer simulation. Instead of the physical audiometer, they rely on the transducer (i.e. Supra aural headphones and/or Bone oscillators) to generate sufficient Sound Pressure Levels.
One great limitation is that the sound cards are not able to reproduce the desired low sound levels. Therefore, the hearing threshold level of a normal hearing person will be limited by the system. A solution to the limitation may be the usage of an external attenuator. However, this may make the product more costly.
With PC-based audiometers only the transducers are calibrated and not the audiometer itself. Calibration standards are available for a limited range of headphones such as TDH39 and HDA200. These headphones don’t attenuate sufficient sound on their own and therefore should be used within a sound booth.
What Is a PC Controlled Audiometer?
Computer controlled refers to standalone audiometers that are controlled by a computer interface. In this case, you have a stand-alone device, connected to your PC. Test information is transferred and shown on the computer screen in real-time and controlled by your PC’s interface devices such as your mouse or keyboard. This has also been referred to as a hybrid audiometer.
Computer controlled audiometers use microprocessors to generate pure tones, masking noise and speech audiometry just as a conventional audiometer. These audiometers are generally connected to a computer patient management software to allow for the saving and retrieval of patient data. Lastly, computer based audiometers offer many advantages in terms of simplicity and flexibility of use over stand-alone audiometers.
The calibration of the test equipment is performed at regular intervals to ensure that it is within calibration. Over and above this, subjective tests of the audiometric equipment are performed daily or weekly to verify calibration.
International audiometric calibration standards are prescribed as a guide for competent laboratories to calibrate the audiometers. The electroacoustic calibration is generally done annually - to ensure precision during testing.
Where does the KUDUwave fall?
The KUDUwave is a PC controlled device, with independent audiometers in each ear cup operated by a computer interface.
PC controlled audiometers are fairly common with the most attractive features including portability. In many cases portability comes at the cost of features and functions, not to mention that they will still require a soundbooth.
What really sets the KUDUwave apart is that it offers an all-in-one, portable solution that offers truly boothless audiometry without compromising on features.