If the results of audiology testing suggest that hearing aids are appropriate, the audiologist will discuss hearing aid evaluation with the patient to address their specific needs. Based on the nature and severity of the hearing loss, and the individual needs and expectations of the patient, the audiologist will make a recommendation for the appropriate hearing aids.
The hearing aid evaluation is a series of tests that have been developed to assess what type of hearing instrument would be most beneficial for an individual’s hearing impairment. Generally, a description of the hearing aid’s specifications is discussed with the client, and the availability of a trial period with the recommended hearing instrument follows.
Hearing Aid EvaluationHearing aid evaluation is a term used to evaluate one’s need for amplification and what type of amplification should be recommended. This is done through the consultation of the hearing test and the hearing questionnaires done by the professional to determine lifestyle, needs, and budget. Some hearing aid evaluations will also include in office demonstrations of the technology.
Behavioral Hearing Aid Tests
Historically, the most common hearing aid performance evaluation was an Aided Audiogram. This is a functional gain measure test where, just like in the pure-tone test previously defined, pure-tones were presented across frequencies in sound field speakers to determine how much gain or volume the hearing aids were providing to improve hearing and allow the patient to hear “near-normal” levels.
Aided Speech Recognition Testing
This test refers to speech recognition testing performed with the patient wearing the hearing aids and the score compared to results obtained prior to the hearing aid fitting. Again, the goal is to determine the amount of gain or volume the hearing aid is providing to ensure improvement in the threshold of audibility for speech. Examples include Speech-in-Noise testing that can be performed pre- and post-fitting.
Standardized, subjective questionnaires like the Abbreviated Patient Hearing Aid Benefit (APHAB) test can offer useful information in measuring hearing aid success. Hearing Aid effectiveness may also be measured by simply asking the patient how the device is helping. Patient will report difficulty communicating in certain environments before they are wearing the hearing aid. The goal of amplification is that their communication will improve after they began wearing the device.
There are a number of valid & useful electroacoustic measurement scales. This testing refers to the measurement of the properties of sound the hearing aid is producing. Electroacoustic verification provides a benchmark for future quality control measures. In general, parameters are set to give the widest possible frequency response range, the maximum gain, and the maximum output.
Real-Ear Measurement (REM)
Real-Ear Measurement is a term used for all measurements done directly in the ear of the hearing aid user. The size and shape of the ear canal influences the output of the hearing aid and can result in over or under amplification, depending on the unique anatomy of the ear canal and the way its resonant characteristics interact with the prescribed gain of the hearing instrument.
The goal of REM is to objectively quantify the acoustic output of a hearing aid in a patient’s ear canal. The measurement requires placement of a probe microphone in the ear canal to measure the sound pressure level (SPL), or gain, provided by the hearing aid. Sounds are presented from a loudspeaker placed in front of the patient. A microphone is located close to the ear to measure the sound’s intensity. A second microphone is placed in the ear canal, close to the eardrum to measure the SPL provided by the hearing instrument.
Hearing Aid Evaluation Expectations
The hearing aid evaluation is usually completed within one hour. Many times the patient may sample several demonstration hearing aids to have a general idea of how amplification sounds.