What type of action does activating healing hymn consume? It is a spell-like ability, but it does not emulate a spell and it doesn't specify in its text what kind of action it uses, so I'm not certain.
Healing Hymn (Complete Champion 47):
If you have 3 or more ranks in a Perform skill, you can use your music or poetics to create an area conducive to healing.
To be affected, an ally must be able to see and hear you perform. The effect lasts as long as you continue performing and for 5 rounds thereafter. An affected ally who casts any conjuration (healing) spell gains a +1 sacred (if you’re good or neutral) or profane (if you’re evil) bonus on the roll for each rank you have in the Perform skill. This ability has no effect on spells cast from wands, scrolls, or other magic items.
In addition, if you use this ability for 1 full minute before you and your allies retire for the night, everyone in the group heals naturally as if he had completed 24 hours of bed rest (thus recovering twice his character level in hit points). If the music is interrupted, the magic of the song is lost.
Either use of healing hymn counts as one daily use of your bardic music ability.
Spell Like Abilities:
Spell-Like Abilities (Sp) Usually, a spell-like ability works just like the spell of that name. A few spell-like abilities are unique; these are explained in the text where they are described.
A spell-like ability has no verbal, somatic, or material component, nor does it require a focus or have an XP cost. The user activates it mentally. Armor never affects a spell-like ability’s use, even if the ability resembles an arcane spell with a somatic component.
A spell-like ability takes the same amount of time to complete as the spell that it mimics (usually 1 standard action) unless otherwise stated. Spell-like abilities cannot be used to counterspell, nor can they be counterspelled. In all other ways, a spell-like ability functions just like a spell:
Using a spell-like ability while threatened provokes attacks of opportunity. It is possible to make a Concentration check to use a spell-like ability defensively and avoid provoking an attack of opportunity. A spell-like ability can be disrupted just as a spell can be. Spell-like abilities are subject to spell resistance and to being dispelled by dispel magic. They do not function in areas where magic is suppressed or negated.
A spell-like ability usually has a limit on how often it can be used. A spell-like ability that can be used at will has no use limit.
For creatures with spell-like abilities, a designated caster level defines how difficult it is to dispel their spell-like effects and to define any level-dependent variables (such as range and duration) the abilities might have. The creature’s caster level never affects which spell-like abilities the creature has; sometimes the given caster level is lower than the level a spellcasting character would need to cast the spell of the same name. If no caster level is specified, the caster level is equal to the creature’s Hit Dice. The saving throw (if any) against a spell-like ability is:
10 + the level of the spell the ability resembles or duplicates + the creature’s Cha modifier.
Some spell-like abilities duplicate spells that work differently when cast by characters of different classes. A monster’s spell-like abilities are presumed to be the sorcerer/wizard versions. If the spell in question is not a sorcerer/wizard spell, then default to cleric, druid, bard, paladin, and ranger, in that order.
Some creatures are actually sorcerers of a sort. They cast arcane spells as sorcerers do, using components when required. In fact, an individual creature could have some spell-like abilities and also cast other spells as a sorcerer.