Go back to Nicholas's IPA Machine 
b
Some people find it difficult to hear the difference between b and v;
some can't easily hear the difference between b and p.
Words with the IPA b sound
ball, baby, bell, bed, bin, bond, box, but, butter - and thousands more
Compare b and v
This is the difference between b and v: When you make a b sound, your lips are together; your mouth is closed for a moment.
When you make a v sound, your lips are not together; your bottom lip touches your upper teeth - it does not touch your upper lip.
Compare b and p
Your lips are in the same position for the b sound and the p sound. The difference is that a p sound is more explosive. You can try this with a lighted candle. When you make a p sound, the candle flame should move more. Or you can hold a piece of tissue paper in front of your mouth. It works!