Can I still learn how to sing even with partial hearing loss in my left ear?

Whether you can learn to sing with part hearing loss depends on the percentage of the hearing loss---20%, 40%, etc. However, the first step towards learning to sing is to take face-to-face voice lessons from a qualify voice teacher. The teacher will listen to your singing and offer guidance and feedback about your vocal progress

Here are some tips about finding a voice teacher:

The teacher has an excellent ear, and carefully listens to, and gives you accurate feedback about your voice.

Has an understanding of vocal anatomy, including the respiratory muscles, the larynx and throat structures, and how they affect singing.

Allows you to tape record lessons or exercises in the lesson for take-home practice. Provides you with written exercises when needed.

Is professional in conduct yet personable. You should feel comfortable with this person. You should feel free to ask questions.

While being emotionally supportive, he or she should be able to challenge you to grow as a singer at the same time.

The teacher should be able to explain to you in depth why you are doing each exercise that he or she gives you.

If available go to a recital where this teacher's students are performing. If they mostly sound great then this is probably a very good indication of a competent voice teacher.

Avoid teachers who only take on students who are already professional vocalists. A good teacher can train any voice and would enjoy the challenge of doing so.

The teacher shows genuine interest in you as a singer.

The teacher understands vocal health issues including the need to drink water and monitor the speaking voice

Addresses the need to relax those tensions/muscles that can block good vocal production and vocal freedom.

Is emotionally stable and does not intimidate or talk down to you.

Your voice feels easier and more resonant when working together

Try one singing lesson and ask the teacher for advice.

Singing cannot be taught. Other musical instruments EG. guitar etc. can be taught. For singing you need to have an in born talent. For example Beatles guys never learned how to sing they learnt instruments but could still sing cos they were born with talent. Just like Jim Morrison. SINGING CANNOT BE TAUGHT !!