Chapter 12: Hearing Instruments

Another term for residual auditory capacity is _____.

When a patient requests that you fit one hearing instrument when the hearing loss is bilateral and symmetrical, if you agree, you are _____.

Most people equate hearing with _____.

The hearing instrument should be guaranteed to do what to sound?

Moderately severe hair cell damage is _____.

Most states have a policy that allows new hearing instruments to be returned within 30 days for any reason to receive a full or nearly-full refund.

This law leads to misconceptions regarding: (check all that apply)

Input is the term used to identify _____ sound with respect to the hearing instrument..

The first transducer in the hearing instrument is the _____.

In first generation technology, the next step in the amplification process is the _____ stage.

In the first tranduction, acoustical waves are changed in form to _____.

In the current generation of technology, the transduced acoustical wave moves along to a _____.

The ATD processor converts the signal into _____.

Once the ATD step is complete, the signal now enters the _____ stage.

From the ATD to the amplifier, the sound bits are re-converted by the _____.

Continuing, where it is transduced into acoustical waves by the receiver.

Battery life is rated in _____ per _____.

Rank the following batteries in terms of battery life.

The transducer is an electronic device which changes one form of _____ into another.

The main component of the microphone is a _____ which holds an _____.

An input transducer is an electronic device which acts:

Omnidirectional microphones are designed to receive sounds from:

Directional microphones are made with _____.

Directional microphone patterns are described as variations of _____ schemes on _____.

The nearness of the hearing instrument microphone to the telephone receiver led to the development of _____.

The telecoil is a _____ which changes electromagnetic energy present in the telephone into an _____ signal which the hearing instrument can process as sound.

The effectiveness of directional microphones is due to the following (check all that apply).

SNR is signal to noise ratio. This represents the measured intensity of the unwanted signals compared to the local noise.

The ratio of microphone output directly in front of the listener compared to sounds in a 360 degree circle is called the _____.

A SNR reading of -6 means the signals are _____ when compared to noise being picked up.

Natural hearing is best represented by which microphone scheme?

The higher the SNR, the better the microphone scheme is performing in that particular acoustical environment.

The statistical areas where we locate the intensities and frequencies making up speech is of particular importance with respect to the:

The last transducer in the hearing instrument is the _____.

Receivers are also made up of diaphragms which are magnetic, just like the _____.

The electric, amplified signal passes into the receiver. The diaphragm vibrates in response to the makeup of the _____ in the speaker, which create acoustical wave forms.

Amplifiers provide the _____ of the acoustic signal.

Digital hearing instruments include an integrated circuit.

An integrated circuit with an ATD and a DTA is also known as:

The circuit board is an integrated circuit, which contains resistors, transistors, and other components.

An analog amplifier is a compression based peak limiting amplifier.

The amount of sound that hearing instruments augment through amplification is termed the _____ of the instrument.

The amount of sound energy recordable at the receiver is called the:

Output is measured in:

I + G = _____

In today’s technology, output relative to input is described by the term _____.

Current technology allows the hearing instrument to _____ increased input.

The compression circuit differs from first generation linear amplification technology because linear circuits amplified all input _____.

Linear technology deals with sounds too strong for the amplifier by _____.

The concept with compression hearing instruments is based on the fact that the louder the signal the_____ amplification is needed to insure the output of the instrument remains within the dynamic range.

Compression hearing instruments have the capacity to _____ output by a percentage.

The programmable point at which compression becomes active and loud sounds are reduced by certain amounts is called the _____.

CT [compression kneepoint] and CT [compression threshold] are:

The point at which amplification is no longer linear in nature and the lowest point on input which will trigger a 2 dB reduction in gain is termed the _____.

The amplification algorithm [mathematical instructions] is active and functions over a particular area in the dynamic range. The area is called the _____.

The time delay from the point of sound input which triggers compression until the output level is reached by the instrument is termed _____ time.

The interval of time between compression amplification and the return to linear amplification is termed _____ time.

With compression instrumentation, in order to function properly the samples have to be taken. The sampling loop can be taken either in front of or behind the volume control [VC] in order to be processed. The VC then becomes a factor in whether the CK [compression Kneepoint] is constant or variable.

If the loop is in front of the VC, compression dictates that the CK is _____.

If the loop is behind [after] the VC, compression dictates that the CK changes with the gain but _____ is constant.

Compression limiting circuits limit _____.

Compression limiting circuits function as _____ hearing instruments over the majority of the frequency/intensity spectrum.

Compression limiting circuits are designed to:

WDRC stands for Wide Dynamic Range Compression and is known to make available:

The criteria which lead to high performance in WDRC HI’s are: