CIC (Completely in the Canal)

Our smallest custom hearing instrument, CIC fits securely in the hearing canal. The CIC is nearly invisible to the naked eye, making it perfect for those who are cosmetically conscious. A CIC hearing instrument is often a good choice for a mild to moderately severe hearing loss.

                    Open Fit

Small and cosmetically appealing, Open Fit is ideal for high frequency loss.

 
     

     
  

ITC (In the Canal)

ITE custom hearing instruments fit securely in the outer portion of your ear. This position allows for easy volume adjustments. ITE instruments can be fit with a wide range of circuit options including digital, programmable, and directional microphone.

 


BTE (Behind the Ear)

The BTE fits directly behind the ear. BTE's are ideal for persons who need significant power, made possible by a larger battery compartment. BTE's are also an excellent choice for children, who can quickly outgrow in-the-ear type instruments.



 

Class A Analog Circuitry

 

The Class A amplifier is the amplifier first introduced in hearing aids. Therefore it is the least expensive and best understood amplifier.

Class D Analog Circuitry

The Class D amplifiers are more complicated, but essentially they have an oscillator which oscillates at 220 kHz, this oscillation is divided to create a square wave of 110 kHz. The square wave is further converted to a triangular wave by the integrator, and the amplified audio signal input that we wish to hear is added to the triangular wave via the adder circuit. The circuit contains a "duty cycle modulator" which generates a positive voltage for everything above threshold and a negative voltage for signals below the threshold level. A series of pulses remains. Loud sounds are coded via wide pulses while soft sounds have narrow pulses. The advantage of such a system is that the system is on only when there is an incoming signal present. Consequently, battery life is improved in the Class D amplifier. Also the amplifier is much smaller than either the Class A or B. This amplifier reduces harmonic distortion under higher input levels. The average hearing aid user is able to hear louder sounds with much less distortion when this amplifier is compared to the Class A or B amplifiers. The quality of sound is much improved. Most hearing aid fitters are choosing the Class D amplifier because the hearing aid user will gain much clearer, non-distorted sound, even in noisily situations.

Full Digital

The digital processing circuits are using many of the principles of sound management which are described in the compression circuits listed above. They all are doing some type of sound compression to control how loud the sound get. They usually have adjustments for the kneepoint and the output limiting. They also are able to enhance soft sounds. When the instrument senses speech sounds below your threshold they will increase the sound until you should be able to understand the speech. How long has it been since you have been able to understand when someone whispers?

The digital instrument actually changes the sound from the analog signal into a digital format of zeros and ones. This is where all the sound processing is done. This helps eliminate some of the distortion problems found in analog sound processing. They are also able to sample the incoming sounds. When it finds a "steady state" noise, the instrument will not increase the volume of that sound and will only enhance what it recognizes as speech. Therefore, you usually do much better in noisy situations then with a analog hearing aid circuit.