In the past, educators took for granted that children had the ability to distinguish sounds. Over the past few years there has been a better understanding that not all children have this ability. These children greatly benefit in being given assistance in this area and the push towards phonemic instruction was adapted. Phonemic awareness does not relate to identifying letters but a child's ability to distinguish sounds. I attended a session where a school gave a presentation on how they have included phonemic awareness instruction daily with their kindergarten class. They devoted 10-15 minutes every day to this. They noticed an increase in the children within their school being more successful in learning to read.
I often refer to the site that you will find in the link below because it provides you with a wealth of information on this topic and a video demonstrating instruction in this area. However, in the session I attended the children were given little hand mirrors to observe how their lips and tongue moved when they made the different sounds. They would also hold their hand close to their lips and feel the air movement as they made different sounds. This gave the children an understanding of how and why different sounds are produced.
I have included the link below for more information on this topic. Maybe you can start thinking about using little mirrors in your own phonemic instructional period.