Audiometer home-made

Manual audiometer with XR2206

Technical Manual

GENERAL DESCRIPTION : Basic Audiometer with 7 preset frequency selector, with earphone adaptor, decibel regulator and LCD display. Device with DC power between 10v to 26v, and sine signal generator. The XR-2206 is a monolithic function generator integrated circuit capable of producing high quality sine, square, triangle, ramp, and pulse waveforms of high-stability and accuracy. The output waveforms can be both amplitude and frequency modulated by an external voltage. Frequency of operation can be selected externally over a range of 0.01Hz to more than 1MHz. The circuit is ideally suited for communications, instrumentation, and function generator applications requiring sinusoidal tone, AM, FM, or FSK generation. It has a typical drift specification of 20ppm/°C. The oscillator frequency can be linearly swept over a 2000:1 frequency range with an external control voltage, while maintaining low distortion.[1]

Fig.1 Datasheet information of XR2206

VISUAL LCD DISPLAY

screen with decibels visualization

Fig. 2 LCD display

User's Manual

1. Turn on the audiometer:

Connect by USB port or electrical outlet socket with adapter.

2. Select frequency :

With the switch to select the frequency that you want to evaluate

3. Assign Decibels:

With the Knob Assign the decibels in clockwise direction

4. Connect headphones:

On the adapter input connect the headphones

A practical explaining way to understand how it works is with the following video

REFERENCES:

[1] EXAR Corporation. (2008). Monolithic Function Generator [Ebook]. Fremont. Retrieved from https://www.sparkfun.com/datasheets/Kits/XR2206_104_020808.pdf