i am using a 9V battery with 5V voltage regulator as my supply. So i have to use other type of amp instead of lm386? May i know lm 831 or mc33078 suitable to be a power amp?The LM386 power amplifier is cheap and is used in kids toys. It has hiss which is not good for a hearing aid. Its minimum supply is 4.0V or 5.0V. What will you use to power your hearing aid? Three button or AAA alkaline cells are 4.5V when brand new then drop to 3.0V. An LM386 might not work when the voltage is less than 4.0v or 5.0V. Find a newer amp that will work with a very low supply voltage.
Thanks!